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Shafin Chowdhury
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Mathematics Formula Cheat Sheet

Software Developer & Computer Science Student

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Table of Contents47 topics

A compact but broad reference of the most-used mathematical formulas.

This sheet is designed for quick lookup rather than derivations. It covers school mathematics, higher-secondary mathematics, undergraduate calculus, coordinate geometry, vectors, matrices, complex numbers, sequences and series, probability, statistics, number theory, discrete mathematics, numerical methods, and common applied formulas.

Important: No finite document can literally contain every formula in mathematics—mathematics is an open-ended discipline with infinitely many identities and specialized results. This version aims to cover the standard formulas most useful for students, competitive programming, engineering, computer science, and general mathematical work.


Arithmetic & Foundations

1. Basic Arithmetic

Order of Operations & Arithmetic Properties

No.Property / RuleFormulaConditions / Notes
1Order of OperationsPEMDAS / BODMAS\text{PEMDAS / BODMAS}Parentheses/Brackets →\to Exponents/Orders →\to Multiplication/Division →\to Addition/Subtraction (left-to-right for equal rank)
2Commutative (Addition)a+b=b+aa + b = b + aOrder of terms does not affect sum
3Commutative (Multiplication)ab=baab = baOrder of factors does not affect product
4Associative (Addition)(a+b)+c=a+(b+c)(a + b) + c = a + (b + c)Grouping does not affect sum
5Associative (Multiplication)(ab)c=a(bc)(ab)c = a(bc)Grouping does not affect product
6Distributive (Over Addition)a(b+c)=ab+aca(b + c) = ab + acFactor distributes across sum
7Distributive (Over Subtraction)a(b−c)=ab−aca(b - c) = ab - acFactor distributes across difference
8Additive Identitya+0=aa + 0 = a00 is the additive identity
9Multiplicative Identitya⋅1=aa \cdot 1 = a11 is the multiplicative identity
10Additive Inversea+(−a)=0a + (-a) = 0Opposite value yields zero
11Multiplicative Inversea⋅1a=1a \cdot \frac{1}{a} = 1Reciprocal yields unity (a≠0a \ne 0)

Absolute Value

No.PropertyFormulaConditions / Notes
12Piecewise Definition∣x∣={x,x≥0−x,x<0\vert x\vert = \begin{cases} x, & x \ge 0 \\ -x, & x < 0 \end{cases}Geometric distance from 00 on number line
13Absolute Product∣ab∣=∣a∣∣b∣\vert ab\vert = \vert a\vert \vert b\vertMagnitude of product equals product of magnitudes
14Absolute Quotient∣ab∣=∣a∣∣b∣\left\vert\frac{a}{b}\right\vert = \frac{\vert a\vert}{\vert b\vert}Magnitude of quotient (b≠0b \ne 0)
15Triangle Inequality∣a+b∣≤∣a∣+∣b∣\vert a + b\vert \le \vert a\vert + \vert b\vertUpper bound on magnitude of sum
16Reverse Triangle Inequality∣∣a∣−∣b∣∣≤∣a−b∣\big\vert\vert a\vert - \vert b\vert\big\vert \le \vert a - b\vertLower bound on magnitude of difference

2. Fractions, Ratios, Proportions and Percentages

Fraction Operations

No.OperationFormulaConditions / Notes
17Fraction Additionab+cd=ad+bcbd\frac{a}{b} + \frac{c}{d} = \frac{ad + bc}{bd}b,d≠0b, d \ne 0
18Fraction Subtractionab−cd=ad−bcbd\frac{a}{b} - \frac{c}{d} = \frac{ad - bc}{bd}b,d≠0b, d \ne 0
19Fraction Multiplicationab⋅cd=acbd\frac{a}{b} \cdot \frac{c}{d} = \frac{ac}{bd}b,d≠0b, d \ne 0
20Fraction Divisionab÷cd=ab⋅dc=adbc\frac{a}{b} \div \frac{c}{d} = \frac{a}{b} \cdot \frac{d}{c} = \frac{ad}{bc}b,c,d≠0b, c, d \ne 0

Ratios & Proportions

No.ConceptFormulaConditions / Notes
21Ratio Notationa:b=aba : b = \frac{a}{b}Comparison of two relative quantities (b≠0b \ne 0)
22Proportion Cross-Producta:b=c:d  ⟺  ad=bca : b = c : d \iff ad = bcEquality of two ratios (b,d≠0b, d \ne 0)
23Direct Proportiony∝x  ⟹  y=kxy \propto x \implies y = kxkk is constant of proportionality
24Inverse Proportiony∝1x  ⟹  xy=ky \propto \frac{1}{x} \implies xy = kkk is constant of variation

Percentages

No.MetricFormulaConditions / Notes
25Percentage CalculationPercentage=PartWhole×100%\text{Percentage} = \frac{\text{Part}}{\text{Whole}} \times 100\%Ratio expressed per hundred
26Part from PercentagePart=Percentage100×Whole\text{Part} = \frac{\text{Percentage}}{100} \times \text{Whole}Amount corresponding to percentage rate
27Percentage Change% Change=New−OldOld×100%\%\text{ Change} = \frac{\text{New} - \text{Old}}{\text{Old}} \times 100\%Relative change over baseline
28Successive ChangesNet Change=(a+b+ab100)%\text{Net Change} = \left(a + b + \frac{ab}{100}\right)\%For consecutive percentage changes a%a\% and b%b\%
29Percentage Error% Error=∣Experimental−True∣∣True∣×100%\%\text{ Error} = \frac{\vert\text{Experimental} - \text{True}\vert}{\vert\text{True}\vert} \times 100\%Accuracy relative to standard/true value

3. Powers, Exponents and Radicals

Laws of Exponents

No.LawFormulaConditions / Notes
30Product of Powersaman=am+na^m a^n = a^{m+n}Add exponents when multiplying same base
31Quotient of Powersaman=am−n\frac{a^m}{a^n} = a^{m-n}Subtract exponents (a≠0a \ne 0)
32Power of a Power(am)n=amn(a^m)^n = a^{mn}Multiply inner and outer exponents
33Power of a Product(ab)n=anbn(ab)^n = a^n b^nDistribute exponent across factors
34Power of a Quotient(ab)n=anbn\left(\frac{a}{b}\right)^n = \frac{a^n}{b^n}Distribute exponent across terms (b≠0b \ne 0)
35Zero Exponenta0=1a^0 = 1Nonzero base to the zero power (a≠0a \ne 0)
36Negative Exponenta−n=1ana^{-n} = \frac{1}{a^n}Reciprocal with positive power (a≠0a \ne 0)
37Unit Fractional Exponenta1/n=ana^{1/n} = \sqrt[n]{a}Principal nn-th root (a≥0a \ge 0 for even nn)
38General Rational Exponentam/n=amn=(an)ma^{m/n} = \sqrt[n]{a^m} = (\sqrt[n]{a})^mm,n∈Z,n>0m, n \in \mathbb{Z}, n > 0

Radical Rules & Rationalization

No.PropertyFormulaConditions / Notes
39Radical Productab=ab\sqrt{ab} = \sqrt{a}\sqrt{b}a,b≥0a, b \ge 0
40Radical Quotientab=ab\sqrt{\frac{a}{b}} = \frac{\sqrt{a}}{\sqrt{b}}a≥0,b>0a \ge 0, b > 0
41Root of a Poweramn=am/n\sqrt[n]{a^m} = a^{m/n}Radical to fractional power equivalence
42Nested Radicalsamn=amn\sqrt[n]{\sqrt[m]{a}} = \sqrt[mn]{a}Product of root indices
43Radical Power Inverse(an)n=a(\sqrt[n]{a})^n = aa≥0a \ge 0 if nn is even
44Monomial Rationalization1a=aa\frac{1}{\sqrt{a}} = \frac{\sqrt{a}}{a}Multiply top & bottom by a\sqrt{a}
45Binomial Rationalization1a+b=a−ba2−b\frac{1}{a + \sqrt{b}} = \frac{a - \sqrt{b}}{a^2 - b}Multiply by conjugate (a−b)(a - \sqrt{b})
46Conjugate Product(a+b)(a−b)=a2−b(a + \sqrt{b})(a - \sqrt{b}) = a^2 - bDifference of squares eliminates radical

Algebra

4. Algebraic Identities

Squares & Quadratics

No.IdentityFormulaConditions / Notes
47Square of Sum(a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2Trinomial expansion
48Square of Difference(a−b)2=a2−2ab+b2(a - b)^2 = a^2 - 2ab + b^2Middle term negative
49Difference of Squaresa2−b2=(a+b)(a−b)a^2 - b^2 = (a + b)(a - b)Factoring conjugate binomials
50Sum of Squares (via Sum)a2+b2=(a+b)2−2aba^2 + b^2 = (a + b)^2 - 2abExpressed using sum and product
51Sum of Squares (via Diff)a2+b2=(a−b)2+2aba^2 + b^2 = (a - b)^2 + 2abExpressed using difference and product

Cubes & Higher Powers

No.IdentityFormulaConditions / Notes
52Cube of Sum(a+b)3=a3+3a2b+3ab2+b3(a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3=a3+b3+3ab(a+b)= a^3 + b^3 + 3ab(a + b)
53Cube of Difference(a−b)3=a3−3a2b+3ab2−b3(a - b)^3 = a^3 - 3a^2b + 3ab^2 - b^3=a3−b3−3ab(a−b)= a^3 - b^3 - 3ab(a - b)
54Sum of Cubesa3+b3=(a+b)(a2−ab+b2)a^3 + b^3 = (a + b)(a^2 - ab + b^2)Linear factor with alternating quadratic
55Difference of Cubesa3−b3=(a−b)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2)Linear factor with positive quadratic
56Difference of Fourth Powersa4−b4=(a−b)(a+b)(a2+b2)a^4 - b^4 = (a - b)(a + b)(a^2 + b^2)Iterated difference of squares
57Fourth Power of Sum(a+b)4=a4+4a3b+6a2b2+4ab3+b4(a + b)^4 = a^4 + 4a^3b + 6a^2b^2 + 4ab^3 + b^4Binomial coefficients: 1, 4, 6, 4, 1
58Fourth Power of Difference(a−b)4=a4−4a3b+6a2b2−4ab3+b4(a - b)^4 = a^4 - 4a^3b + 6a^2b^2 - 4ab^3 + b^4Alternating sign expansion

Multi-Variable & General Powers

No.IdentityFormulaConditions / Notes
59Square of Trinomial(a+b+c)2=a2+b2+c2+2(ab+bc+ca)(a + b + c)^2 = a^2 + b^2 + c^2 + 2(ab + bc + ca)Sum of squares + all pairwise products
60Alternating Trinomial Square(a−b−c)2=a2+b2+c2−2ab−2ac+2bc(a - b - c)^2 = a^2 + b^2 + c^2 - 2ab - 2ac + 2bcSign distribution rule
61Sum of Three Cubesa3+b3+c3−3abc=(a+b+c)(a2+b2+c2−ab−bc−ca)a^3 + b^3 + c^3 - 3abc = (a + b + c)(a^2 + b^2 + c^2 - ab - bc - ca)Euler’s factorization identity
62Zero-Sum Cubic Special Casea+b+c=0  ⟹  a3+b3+c3=3abca + b + c = 0 \implies a^3 + b^3 + c^3 = 3abcDirect consequence of Euler’s identity
63General Difference of nn-th Powersan−bn=(a−b)(an−1+an−2b+⋯+bn−1)a^n - b^n = (a - b)(a^{n-1} + a^{n-2}b + \cdots + b^{n-1})Valid for all positive integers nn
64General Sum of nn-th Powersan+bn=(a+b)(an−1−an−2b+⋯+bn−1)a^n + b^n = (a + b)(a^{n-1} - a^{n-2}b + \cdots + b^{n-1})Valid for odd integers nn

5. Polynomials

Theorems & Quadratics

No.Concept / FormFormulaConditions / Notes
65Polynomial FormP(x)=anxn+an−1xn−1+⋯+a1x+a0P(x) = a_n x^n + a_{n-1}x^{n-1} + \cdots + a_1 x + a_0Degree nn with leading coefficient an≠0a_n \ne 0
66Remainder TheoremRemainder=P(a)\text{Remainder} = P(a)Remainder when P(x)P(x) is divided by (x−a)(x - a)
67Factor TheoremP(a)=0  ⟺  (x−a) is a factor of P(x)P(a) = 0 \iff (x - a) \text{ is a factor of } P(x)Root-factor equivalence
68Quadratic Formulax=−b±b2−4ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}Roots of ax2+bx+c=0ax^2 + bx + c = 0 (a≠0a \ne 0)
69Quadratic DiscriminantΔ=b2−4ac\Delta = b^2 - 4acDetermines nature and multiplicity of roots
70Vieta’s Sum of Roots (Quadratic)α+β=−ba\alpha + \beta = -\frac{b}{a}Sum of roots of ax2+bx+c=0ax^2 + bx + c = 0
71Vieta’s Product of Roots (Quadratic)αβ=ca\alpha\beta = \frac{c}{a}Product of roots of ax2+bx+c=0ax^2 + bx + c = 0
72Factored Quadratic Formax2+bx+c=a(x−α)(x−β)ax^2 + bx + c = a(x - \alpha)(x - \beta)Factorization via roots α,β\alpha, \beta

Cubic Root Relations (Vieta’s Formulas)

No.RelationFormulaConditions / Notes
73Sum of Rootsα+β+γ=−ba\alpha + \beta + \gamma = -\frac{b}{a}For ax3+bx2+cx+d=0ax^3 + bx^2 + cx + d = 0
74Sum of Pairwise Productsαβ+βγ+γα=ca\alpha\beta + \beta\gamma + \gamma\alpha = \frac{c}{a}Pairwise root products
75Product of Rootsαβγ=−da\alpha\beta\gamma = -\frac{d}{a}Product of all three roots

6. Equations and Inequalities

Linear & Systems of Equations

No.Form / ConceptFormulaConditions / Notes
76Linear Equationax+b=0  ⟹  x=−baax + b = 0 \implies x = -\frac{b}{a}a≠0a \ne 0
77System Determinant DDD=a1b2−a2b1D = a_1 b_2 - a_2 b_1Determinant of 2×22\times 2 coefficient matrix
78Cramer’s Rule for xxx=c1b2−c2b1Dx = \frac{c_1 b_2 - c_2 b_1}{D}Unique solution when D≠0D \ne 0
79Cramer’s Rule for yyy=a1c2−a2c1Dy = \frac{a_1 c_2 - a_2 c_1}{D}Unique solution when D≠0D \ne 0

Quadratic Nature & Parabola Vertex

No.FeatureFormulaConditions / Notes
80Two Distinct Real RootsΔ=b2−4ac>0\Delta = b^2 - 4ac > 0Graph intersects xx-axis twice
81One Repeated Real RootΔ=b2−4ac=0\Delta = b^2 - 4ac = 0Graph tangent to xx-axis at double root
82Complex Conjugate RootsΔ=b2−4ac<0\Delta = b^2 - 4ac < 0No real roots; graph does not touch xx-axis
83Parabola Vertex xx-Coordinatexv=−b2ax_v = -\frac{b}{2a}Axis of symmetry: x=−b2ax = -\frac{b}{2a}
84Parabola Vertex yy-Coordinateyv=f(−b2a)=4ac−b24ay_v = f\left(-\frac{b}{2a}\right) = \frac{4ac - b^2}{4a}Extremum value of quadratic function
85Parabola Vertex Formy=a(x−h)2+ky = a(x - h)^2 + kVertex located at (h,k)(h, k)

Absolute-Value Equations & Inequalities

No.ExpressionSolution / Equivalent FormConditions / Notes
86Absolute Value Equality∣x∣=a  ⟹  x=±a\vert x\vert = a \implies x = \pm aValid for a≥0a \ge 0
87Absolute Value Less-Than∣x∣<a  ⟺  −a<x<a\vert x\vert < a \iff -a < x < aBounded interval (a>0a > 0)
88Absolute Value Greater-Than∣x∣>a  ⟺  x<−a or x>a\vert x\vert > a \iff x < -a \text{ or } x > aDisjoint exterior rays (a>0a > 0)

7. Logarithms

Definitions & Core Properties

No.Property / RuleFormulaConditions / Notes
89Logarithm Definitionlog⁡ab=c  ⟺  ac=b\log_a b = c \iff a^c = ba>0,a≠1,b>0a > 0, a \ne 1, b > 0
90Logarithm of 1log⁡a1=0\log_a 1 = 0a0=1a^0 = 1
91Logarithm of Baselog⁡aa=1\log_a a = 1a1=aa^1 = a
92Log of Base Powerlog⁡a(ax)=x\log_a(a^x) = xInverse cancellation law
93Base to Log Poweralog⁡ax=xa^{\log_a x} = xInverse cancellation law (x>0x > 0)

Operational Laws & Base Conversion

No.LawFormulaConditions / Notes
94Product Rulelog⁡a(xy)=log⁡ax+log⁡ay\log_a(xy) = \log_a x + \log_a yx,y>0x, y > 0
95Quotient Rulelog⁡a(xy)=log⁡ax−log⁡ay\log_a\left(\frac{x}{y}\right) = \log_a x - \log_a yx,y>0x, y > 0
96Power Rulelog⁡a(xr)=rlog⁡ax\log_a(x^r) = r\log_a xx>0x > 0
97Change of Base Formulalog⁡ax=log⁡bxlog⁡ba\log_a x = \frac{\log_b x}{\log_b a}Convert to any convenient base b>0,b≠1b > 0, b \ne 1
98Change to Natural Loglog⁡ax=ln⁡xln⁡a\log_a x = \frac{\ln x}{\ln a}Base ee conversion
99Change to Common Loglog⁡ax=log⁡xlog⁡a\log_a x = \frac{\log x}{\log a}Base 1010 conversion
100Reciprocal Identitylog⁡ab=1log⁡ba\log_a b = \frac{1}{\log_b a}Inverts base and argument (b≠1b \ne 1)
101Natural Log Definitionln⁡x=log⁡ex\ln x = \log_e xBase e≈2.71828e \approx 2.71828
102Exponential-Log Identityeln⁡x=x and ln⁡(ex)=xe^{\ln x} = x \text{ and } \ln(e^x) = xx>0x > 0 for eln⁡xe^{\ln x}

8. Sequences and Series

Arithmetic Progression (AP)

No.Form / ConceptFormulaConditions / Notes
103nn-th Term of APan=a+(n−1)da_n = a + (n - 1)dFirst term aa, common difference dd
104Sum of First nn Terms (with dd)Sn=n2[2a+(n−1)d]S_n = \frac{n}{2}[2a + (n - 1)d]Total sum of nn terms
105Sum of First nn Terms (with ll)Sn=n2(a+l)S_n = \frac{n}{2}(a + l)l=anl = a_n is the last term
106Arithmetic MeanAM=a+b2\text{AM} = \frac{a + b}{2}Midpoint between aa and bb

Geometric Progression (GP)

No.Form / ConceptFormulaConditions / Notes
107nn-th Term of GPan=arn−1a_n = a r^{n-1}First term aa, common ratio rr
108Finite GP Sum (r≠1r \ne 1)Sn=a1−rn1−r=arn−1r−1S_n = a\frac{1 - r^n}{1 - r} = a\frac{r^n - 1}{r - 1}r≠1r \ne 1
109Finite GP Sum (r=1r = 1)Sn=naS_n = naIdentical repeated terms
110Infinite Geometric SeriesS∞=a1−rS_\infty = \frac{a}{1 - r}Converges iff ∣r∣<1\vert r\vert < 1
111Geometric MeanGM=ab\text{GM} = \sqrt{ab}a,b>0a, b > 0

Harmonic Progression & Standard Series Sums

No.Formula / SeriesExpressionConditions / Notes
112Harmonic Progression Definitiona,b,c∈HP  ⟺  1a,1b,1c∈APa, b, c \in \text{HP} \iff \frac{1}{a}, \frac{1}{b}, \frac{1}{c} \in \text{AP}Reciprocal sequence form
113Harmonic Mean (Two Numbers)HM=2aba+b\text{HM} = \frac{2ab}{a + b}a,b>0a, b > 0
114Harmonic Mean (nn Numbers)HM=n∑i=1n1xi\text{HM} = \frac{n}{\sum_{i=1}^n \frac{1}{x_i}}Reciprocal of average of reciprocals
115AM-GM-HM InequalityAM≥GM≥HM\text{AM} \ge \text{GM} \ge \text{HM}Equality holds iff all terms are equal
116Sum of First nn Integers∑k=1nk=n(n+1)2\sum_{k=1}^n k = \frac{n(n + 1)}{2}Triangular numbers
117Sum of First nn Squares∑k=1nk2=n(n+1)(2n+1)6\sum_{k=1}^n k^2 = \frac{n(n + 1)(2n + 1)}{6}Sum of squares formula
118Sum of First nn Cubes∑k=1nk3=[n(n+1)2]2\sum_{k=1}^n k^3 = \left[\frac{n(n + 1)}{2}\right]^2Square of the sum of integers

9. Binomial Theorem

No.Formula / IdentityExpressionConditions / Notes
119Binomial Expansion(a+b)n=∑k=0n(nk)an−kbk(a + b)^n = \sum_{k=0}^n \binom{n}{k} a^{n-k} b^kNonnegative integer nn
120Binomial Coefficient(nk)=n!k!(n−k)!\binom{n}{k} = \frac{n!}{k!(n - k)!}Combinations formula
121General Term Tk+1T_{k+1}Tk+1=(nk)an−kbkT_{k+1} = \binom{n}{k} a^{n-k} b^k(k+1)(k+1)-th term of expansion
122Boundary Values(n0)=(nn)=1\binom{n}{0} = \binom{n}{n} = 1Endpoints of row in Pascal’s triangle
123Symmetry Identity(nk)=(nn−k)\binom{n}{k} = \binom{n}{n - k}Symmetry of Pascal’s triangle
124Pascal’s Recurrence(nk)=(n−1k)+(n−1k−1)\binom{n}{k} = \binom{n-1}{k} + \binom{n-1}{k-1}Additive rule of Pascal’s triangle
125Sum of Coefficients∑k=0n(nk)=2n\sum_{k=0}^n \binom{n}{k} = 2^nTotal number of subsets of nn elements
126Alternating Coefficient Sum∑k=0n(−1)k(nk)=0\sum_{k=0}^n (-1)^k \binom{n}{k} = 0Valid for n>0n > 0

10. Permutations and Combinations

No.Concept / RuleFormulaConditions / Notes
127Factorial Definitionn!=n(n−1)(n−2)⋯2⋅1n! = n(n - 1)(n - 2)\cdots 2\cdot 1Product of first nn positive integers
128Factorial of Zero0!=10! = 1By definition / empty product
129Permutations without RepetitionnPr=n!(n−r)!{}^n P_r = \frac{n!}{(n - r)!}Ordered arrangements of rr from nn distinct
130Combinations without RepetitionnCr=(nr)=n!r!(n−r)!{}^n C_r = \binom{n}{r} = \frac{n!}{r!(n - r)!}Unordered selections of rr from nn distinct
131Permutation-Combination RelationnPr=nCr⋅r!{}^n P_r = {}^n C_r \cdot r!Accounts for r!r! internal orderings
132Permutations with Repetitionn!n1!n2!⋯nk!\frac{n!}{n_1! n_2! \cdots n_k!}Groups of identical objects of sizes nin_i
133Circular Permutations (Distinct)(n−1)!(n - 1)!Distinct clockwise vs counterclockwise
134Circular Permutations (Unoriented)(n−1)!2\frac{(n - 1)!}{2}Flipping allowed (e.g. bead necklace)
135Combinations with Repetition(n+r−1r)\binom{n + r - 1}{r}Stars and bars selection of rr items from nn types

11. Set Theory

No.Law / IdentityFormulaConditions / Notes
136Inclusion-Exclusion (2 Sets)∣A∪B∣=∣A∣+∣B∣−∣A∩B∣\vert A \cup B\vert = \vert A\vert + \vert B\vert - \vert A \cap B\vertPrevents double-counting intersection
137Inclusion-Exclusion (3 Sets)∣A∪B∪C∣=∣A∣+∣B∣+∣C∣−∑∣A∩B∣+∣A∩B∩C∣\vert A \cup B \cup C\vert = \vert A\vert + \vert B\vert + \vert C\vert - \sum \vert A \cap B\vert + \vert A \cap B \cap C\vertAlternating inclusion-exclusion
138Complement Cardinality∣Ac∣=∣U∣−∣A∣\vert A^c\vert = \vert U\vert - \vert A\vertElements outside AA in universe UU
139Set DifferenceA−B=A∩BcA - B = A \cap B^cElements in AA but not in BB
140De Morgan’s Law (Union)(A∪B)c=Ac∩Bc(A \cup B)^c = A^c \cap B^cComplement of union is intersection of complements
141De Morgan’s Law (Intersection)(A∩B)c=Ac∪Bc(A \cap B)^c = A^c \cup B^cComplement of intersection is union of complements
142Cartesian Product Cardinality∣A×B∣=∣A∣∣B∣\vert A \times B\vert = \vert A\vert \vert B\vertOrdered pairs (a,b)(a, b)
143Power Set Cardinality∣P(A)∣=2n\vert\mathcal{P}(A)\vert = 2^nTotal distinct subsets of set of size nn

12. Functions

No.ConceptFormulaConditions / Notes
144Composite Function(f∘g)(x)=f(g(x))(f \circ g)(x) = f(g(x))Output of gg becomes input to ff
145Inverse Function Identityf(f−1(x))=x and f−1(f(x))=xf(f^{-1}(x)) = x \text{ and } f^{-1}(f(x)) = xBidirectional cancellation
146Even Functionf(−x)=f(x)f(-x) = f(x)Symmetric about the yy-axis
147Odd Functionf(−x)=−f(x)f(-x) = -f(x)Symmetric about the origin (rotational)
148Average Rate of Changef(b)−f(a)b−a\frac{f(b) - f(a)}{b - a}Secant line slope over [a,b][a, b]
149Linear Functionf(x)=mx+cf(x) = mx + cConstant slope mm, yy-intercept cc

Geometry

13. Coordinate Geometry

No.Formula NameFormulaConditions / Notes
150Distance Formulad=(x2−x1)2+(y2−y1)2d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}Euclidean distance between P1(x1,y1)P_1(x_1, y_1) and P2(x2,y2)P_2(x_2, y_2)
151Midpoint FormulaM=(x1+x22,y1+y22)M = \left(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}\right)Halfway point of line segment
152Internal Section FormulaP=(mx2+nx1m+n,my2+ny1m+n)P = \left(\frac{mx_2 + nx_1}{m + n}, \frac{my_2 + ny_1}{m + n}\right)Divides segment internally in ratio m:nm:n
153External Section FormulaP=(mx2−nx1m−n,my2−ny1m−n)P = \left(\frac{mx_2 - nx_1}{m - n}, \frac{my_2 - ny_1}{m - n}\right)Divides segment externally in ratio m:nm:n (m≠nm \ne n)
154Triangle CentroidG=(x1+x2+x33,y1+y2+y33)G = \left(\frac{x_1 + x_2 + x_3}{3}, \frac{y_1 + y_2 + y_3}{3}\right)Intersection of three medians
155Area from CoordinatesA=12∣x1(y2−y3)+x2(y3−y1)+x3(y1−y2)∣A = \frac{1}{2}\vert x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2)\vertShoelace formula for vertices (xi,yi)(x_i, y_i)
156Collinearity Conditionx1(y2−y3)+x2(y3−y1)+x3(y1−y2)=0x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2) = 0Area of triangle is zero iff points are collinear

14. Straight Lines

No.Form / ConceptEquation / FormulaConditions / Notes
157Slope of Linem=y2−y1x2−x1m = \frac{y_2 - y_1}{x_2 - x_1}Line through (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) (x1≠x2x_1 \ne x_2)
158Point-Slope Formy−y1=m(x−x1)y - y_1 = m(x - x_1)Line through (x1,y1)(x_1, y_1) with slope mm
159Slope-Intercept Formy=mx+cy = mx + cSlope mm, yy-intercept (0,c)(0, c)
160Two-Point Formy−y1=y2−y1x2−x1(x−x1)y - y_1 = \frac{y_2 - y_1}{x_2 - x_1}(x - x_1)Line passing through two designated points
161Intercept Formxa+yb=1\frac{x}{a} + \frac{y}{b} = 1xx-intercept aa, yy-intercept bb (a,b≠0a, b \ne 0)
162General Form SlopeAx+By+C=0  ⟹  m=−ABAx + By + C = 0 \implies m = -\frac{A}{B}Slope of general linear form (B≠0B \ne 0)
163Angle Between Linestan⁡θ=∣m2−m11+m1m2∣\tan\theta = \left\vert\frac{m_2 - m_1}{1 + m_1 m_2}\right\vertAcute angle between slopes m1,m2m_1, m_2
164Perpendicular Linesm1m2=−1m_1 m_2 = -1Slopes are negative reciprocals
165Parallel Linesm1=m2m_1 = m_2Slopes are equal
166Point to Line Distanced=∣Ax1+By1+C∣A2+B2d = \frac{\vert Ax_1 + By_1 + C\vert}{\sqrt{A^2 + B^2}}Perpendicular distance from (x1,y1)(x_1, y_1) to Ax+By+C=0Ax + By + C = 0
167Distance Between Parallel Linesd=∣C1−C2∣A2+B2d = \frac{\vert C_1 - C_2\vert}{\sqrt{A^2 + B^2}}Between Ax+By+C1=0Ax + By + C_1 = 0 and Ax+By+C2=0Ax + By + C_2 = 0

15. Circles

No.Property / FormFormulaConditions / Notes
168Standard Equation(x−h)2+(y−k)2=r2(x - h)^2 + (y - k)^2 = r^2Center (h,k)(h, k), radius rr
169Center at Originx2+y2=r2x^2 + y^2 = r^2Center (0,0)(0, 0), radius rr
170General Equation Center(−D2,−E2)\left(-\frac{D}{2}, -\frac{E}{2}\right)For x2+y2+Dx+Ey+F=0x^2 + y^2 + Dx + Ey + F = 0
171General Equation Radiusr=12D2+E2−4Fr = \frac{1}{2}\sqrt{D^2 + E^2 - 4F}Real circle requires D2+E2−4F>0D^2 + E^2 - 4F > 0
172CircumferenceC=2πr=πdC = 2\pi r = \pi dPerimeter of circle
173AreaA=πr2=πd24A = \pi r^2 = \frac{\pi d^2}{4}Total enclosed surface
174Arc Length (Radians)s=rθs = r\thetaAngle θ\theta in radians
175Arc Length (Degrees)s=θ360∘2πrs = \frac{\theta}{360^\circ} 2\pi rAngle θ\theta in degrees
176Sector Area (Radians)A=12r2θA = \frac{1}{2}r^2\thetaCentral angle θ\theta in radians
177Sector Area (Degrees)A=θ360∘πr2A = \frac{\theta}{360^\circ}\pi r^2Central angle θ\theta in degrees
178Chord Lengthc=2rsin⁡(θ2)c = 2r\sin\left(\frac{\theta}{2}\right)Central angle θ\theta

16. Conic Sections

Parabola

No.Form / PropertyFormulaConditions / Notes
179Horizontal Standard Parabolay2=4axy^2 = 4axOpens right (a>0a > 0) or left (a<0a < 0)
180Vertical Standard Parabolax2=4ayx^2 = 4ayOpens up (a>0a > 0) or down (a<0a < 0)
181Parabola Focus (y2=4axy^2=4ax)Focus: (a,0)(a, 0)Directrix: x=−ax = -a
182Parabola Vertex & Latus RectumVertex: (0,0)(0, 0), Latus Rectum: 4a4aFocal chord length perpendicular to axis

Ellipse

No.Form / PropertyFormulaConditions / Notes
183Horizontal Ellipse Equationx2a2+y2b2=1\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1Major axis horizontal (a>b>0a > b > 0)
184Vertical Ellipse Equationx2b2+y2a2=1\frac{x^2}{b^2} + \frac{y^2}{a^2} = 1Major axis vertical (a>b>0a > b > 0)
185Focal Distance Relationc2=a2−b2c^2 = a^2 - b^2cc is distance from center to foci
186Eccentricitye=ca=1−b2a2e = \frac{c}{a} = \sqrt{1 - \frac{b^2}{a^2}}0<e<10 < e < 1 for an ellipse
187Foci Coordinates(\pm c, 0)Foci located on major axis
188Ellipse AreaA=πabA = \pi abTotal enclosed area

Hyperbola

No.Form / PropertyFormulaConditions / Notes
189Horizontal Hyperbola Equationx2a2−y2b2=1\frac{x^2}{a^2} - \frac{y^2}{b^2} = 1Transverse axis on xx-axis
190Vertical Hyperbola Equationy2a2−x2b2=1\frac{y^2}{a^2} - \frac{x^2}{b^2} = 1Transverse axis on yy-axis
191Focal Distance Relationc2=a2+b2c^2 = a^2 + b^2cc is distance from center to foci
192Eccentricitye=ca=1+b2a2e = \frac{c}{a} = \sqrt{1 + \frac{b^2}{a^2}}e>1e > 1 for a hyperbola
193Asymptotes (Horizontal Form)y=±baxy = \pm \frac{b}{a}xSlant asymptotes through origin
194Asymptotes (Vertical Form)y=±abxy = \pm \frac{a}{b}xSlant asymptotes through origin

17. Plane Geometry

No.Concept / TheoremFormulaConditions / Notes
195Straight Angle180∘=π rad180^\circ = \pi \text{ rad}Angle on a straight line
196Full Revolution360∘=2π rad360^\circ = 2\pi \text{ rad}Complete circular angle around a point
197Complementary AnglesA+B=90∘A + B = 90^\circTwo angles sum to right angle
198Supplementary AnglesA+B=180∘A + B = 180^\circTwo angles sum to straight angle
199Interior Angle Sum (nn-gon)S=(n−2)180∘S = (n - 2)180^\circTotal interior angles of any nn-sided polygon
200Regular nn-gon Interior Angleθint=(n−2)180∘n\theta_{\text{int}} = \frac{(n - 2)180^\circ}{n}Each interior angle of regular polygon
201Sum of Exterior AnglesSext=360∘S_{\text{ext}} = 360^\circExterior angles sum to 360∘360^\circ for any convex polygon
202Regular nn-gon Exterior Angleθext=360∘n\theta_{\text{ext}} = \frac{360^\circ}{n}Each exterior angle of regular polygon
203Number of DiagonalsD=n(n−3)2D = \frac{n(n - 3)}{2}Total diagonals connecting non-adjacent vertices
204Similar Figures Area RatioA2A1=k2\frac{A_2}{A_1} = k^2For linear scale factor k=L2L1k = \frac{L_2}{L_1}
205Similar Figures Volume RatioV2V1=k3\frac{V_2}{V_1} = k^3For linear scale factor k=L2L1k = \frac{L_2}{L_1}

18. Triangles

No.Formula NameFormulaConditions / Notes
206Basic AreaA=12bhA = \frac{1}{2}bhBase bb, perpendicular height hh
207Semiperimeters=a+b+c2s = \frac{a + b + c}{2}Half of triangle perimeter
208Heron’s FormulaA=s(s−a)(s−b)(s−c)A = \sqrt{s(s - a)(s - b)(s - c)}Area from three side lengths a,b,ca, b, c
209Equilateral Triangle Heighth=32ah = \frac{\sqrt{3}}{2}aFor side length aa
210Equilateral Triangle AreaA=34a2A = \frac{\sqrt{3}}{4}a^2Area of equilateral triangle
211Pythagorean Theorema2+b2=c2a^2 + b^2 = c^2Right triangle with hypotenuse cc
212Law of Sinesasin⁡A=bsin⁡B=csin⁡C=2R\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} = 2RRR is circumradius
213Law of Cosinesa2=b2+c2−2bccos⁡Aa^2 = b^2 + c^2 - 2bc\cos ASolves SAS and SSS configurations
214Area via Sine (SAS)A=12bcsin⁡A=12casin⁡B=12absin⁡CA = \frac{1}{2}bc\sin A = \frac{1}{2}ca\sin B = \frac{1}{2}ab\sin CArea from two sides and included angle
215Circumradius FormulaR=abc4AR = \frac{abc}{4A}Radius of circumscribed circle
216Inradius Formular=As  ⟹  A=rsr = \frac{A}{s} \implies A = rsRadius of inscribed circle
217Euler’s Triangle RelationOI2=R(R−2r)OI^2 = R(R - 2r)Distance between circumcenter OO and incenter II
218Median Length (to side aa)ma=122b2+2c2−a2m_a = \frac{1}{2}\sqrt{2b^2 + 2c^2 - a^2}Apollonius theorem for median length
219Angle Bisector (to side aa)ta=2bccos⁡(A/2)b+ct_a = \frac{2bc\cos(A/2)}{b + c}Internal bisector of angle AA

19. Quadrilaterals and Polygons

No.ShapeProperty / FormulaConditions / Notes
220SquareP=4a,  A=a2,  d=a2P = 4a,\; A = a^2,\; d = a\sqrt{2}Side length aa, diagonal dd
221RectangleP=2(l+w),  A=lw,  d=l2+w2P = 2(l + w),\; A = lw,\; d = \sqrt{l^2 + w^2}Length ll, width ww, diagonal dd
222ParallelogramA=bh,  P=2(a+b)A = bh,\; P = 2(a + b)Base bb, height hh, adjacent side aa
223RhombusA=12d1d2,  P=4aA = \frac{1}{2}d_1 d_2,\; P = 4aDiagonals d1,d2d_1, d_2 are perpendicular
224TrapezoidA=12(a+b)hA = \frac{1}{2}(a + b)hParallel bases a,ba, b with height hh
225KiteA=12d1d2A = \frac{1}{2}d_1 d_2Diagonals d1,d2d_1, d_2 are perpendicular

20. 3D Geometry and Mensuration

No.SolidFormulasConditions / Notes
226CubeV=a3,  S=6a2,  d=a3V = a^3,\; S = 6a^2,\; d = a\sqrt{3}Edge aa, total surface area SS, space diagonal dd
227Rectangular Prism (Cuboid)V=lwh,  S=2(lw+lh+wh),  d=l2+w2+h2V = lwh,\; S = 2(lw + lh + wh),\; d = \sqrt{l^2 + w^2 + h^2}Length ll, width ww, height hh
228Right Circular CylinderV=πr2h,  CSA=2πrh,  TSA=2πr(h+r)V = \pi r^2 h,\; \text{CSA} = 2\pi rh,\; \text{TSA} = 2\pi r(h + r)Base radius rr, height hh
229Right Circular Conel=r2+h2,  V=13πr2h,  CSA=πrl,  TSA=πr(l+r)l = \sqrt{r^2 + h^2},\; V = \frac{1}{3}\pi r^2 h,\; \text{CSA} = \pi rl,\; \text{TSA} = \pi r(l + r)Slant height ll, radius rr, vertical height hh
230SphereS=4πr2,  V=43πr3S = 4\pi r^2,\; V = \frac{4}{3}\pi r^3Surface area SS, volume VV
231HemisphereCSA=2πr2,  TSA=3πr2,  V=23πr3\text{CSA} = 2\pi r^2,\; \text{TSA} = 3\pi r^2,\; V = \frac{2}{3}\pi r^3Curved and total surface area
232Right PrismV=Bh,  LSA=PbasehV = Bh,\; \text{LSA} = P_{\text{base}} hBase area BB, base perimeter PbaseP_{\text{base}}
233Regular PyramidV=13BhV = \frac{1}{3}BhBase area BB, vertical height hh

Trigonometry

21. Trigonometry

Right-Triangle Ratios & Reciprocals

No.Ratio / FunctionFormulaConditions / Notes
234Sine Ratiosin⁡θ=OppositeHypotenuse\sin\theta = \frac{\text{Opposite}}{\text{Hypotenuse}}Right triangle definition
235Cosine Ratiocos⁡θ=AdjacentHypotenuse\cos\theta = \frac{\text{Adjacent}}{\text{Hypotenuse}}Right triangle definition
236Tangent Ratiotan⁡θ=OppositeAdjacent\tan\theta = \frac{\text{Opposite}}{\text{Adjacent}}Right triangle definition
237Cosecant Ratiocsc⁡θ=1sin⁡θ\csc\theta = \frac{1}{\sin\theta}Reciprocal of sine
238Secant Ratiosec⁡θ=1cos⁡θ\sec\theta = \frac{1}{\cos\theta}Reciprocal of cosine
239Cotangent Ratiocot⁡θ=1tan⁡θ\cot\theta = \frac{1}{\tan\theta}Reciprocal of tangent
240Tangent Quotienttan⁡θ=sin⁡θcos⁡θ\tan\theta = \frac{\sin\theta}{\cos\theta}Ratio of sine to cosine
241Cotangent Quotientcot⁡θ=cos⁡θsin⁡θ\cot\theta = \frac{\cos\theta}{\sin\theta}Ratio of cosine to sine

Pythagorean, Parity & Cofunction Identities

No.IdentityFormulaConditions / Notes
242Pythagorean Identity Isin⁡2θ+cos⁡2θ=1\sin^2\theta + \cos^2\theta = 1Fundamental identity on unit circle
243Pythagorean Identity II1+tan⁡2θ=sec⁡2θ1 + \tan^2\theta = \sec^2\thetaDivide by cos⁡2θ\cos^2\theta
244Pythagorean Identity III1+cot⁡2θ=csc⁡2θ1 + \cot^2\theta = \csc^2\thetaDivide by sin⁡2θ\sin^2\theta
245Sine Parity (Odd)sin⁡(−x)=−sin⁡x\sin(-x) = -\sin xOdd function
246Cosine Parity (Even)cos⁡(−x)=cos⁡x\cos(-x) = \cos xEven function
247Tangent Parity (Odd)tan⁡(−x)=−tan⁡x\tan(-x) = -\tan xOdd function
248Cotangent Parity (Odd)cot⁡(−x)=−cot⁡x\cot(-x) = -\cot xOdd function
249Secant Parity (Even)sec⁡(−x)=sec⁡x\sec(-x) = \sec xEven function
250Cosecant Parity (Odd)csc⁡(−x)=−csc⁡x\csc(-x) = -\csc xOdd function
251Sine Cofunctionsin⁡(π2−θ)=cos⁡θ\sin\left(\frac{\pi}{2} - \theta\right) = \cos\thetaComplementary angle relation
252Cosine Cofunctioncos⁡(π2−θ)=sin⁡θ\cos\left(\frac{\pi}{2} - \theta\right) = \sin\thetaComplementary angle relation
253Tangent Cofunctiontan⁡(π2−θ)=cot⁡θ\tan\left(\frac{\pi}{2} - \theta\right) = \cot\thetaComplementary angle relation

Compound, Multiple & Half-Angle Formulas

No.Identity NameFormulaConditions / Notes
254Sine of Sumsin⁡(A+B)=sin⁡Acos⁡B+cos⁡Asin⁡B\sin(A + B) = \sin A\cos B + \cos A\sin BCompound angle formula
255Sine of Differencesin⁡(A−B)=sin⁡Acos⁡B−cos⁡Asin⁡B\sin(A - B) = \sin A\cos B - \cos A\sin BCompound angle formula
256Cosine of Sumcos⁡(A+B)=cos⁡Acos⁡B−sin⁡Asin⁡B\cos(A + B) = \cos A\cos B - \sin A\sin BCompound angle formula
257Cosine of Differencecos⁡(A−B)=cos⁡Acos⁡B+sin⁡Asin⁡B\cos(A - B) = \cos A\cos B + \sin A\sin BCompound angle formula
258Tangent of Sumtan⁡(A+B)=tan⁡A+tan⁡B1−tan⁡Atan⁡B\tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A\tan B}Compound angle formula
259Tangent of Differencetan⁡(A−B)=tan⁡A−tan⁡B1+tan⁡Atan⁡B\tan(A - B) = \frac{\tan A - \tan B}{1 + \tan A\tan B}Compound angle formula
260Sine Double Anglesin⁡2θ=2sin⁡θcos⁡θ\sin 2\theta = 2\sin\theta\cos\thetaDouble angle formula
261Cosine Double Angle (I)cos⁡2θ=cos⁡2θ−sin⁡2θ\cos 2\theta = \cos^2\theta - \sin^2\thetaDouble angle formula
262Cosine Double Angle (II)cos⁡2θ=2cos⁡2θ−1\cos 2\theta = 2\cos^2\theta - 1Cosine-only form
263Cosine Double Angle (III)cos⁡2θ=1−2sin⁡2θ\cos 2\theta = 1 - 2\sin^2\thetaSine-only form
264Tangent Double Angletan⁡2θ=2tan⁡θ1−tan⁡2θ\tan 2\theta = \frac{2\tan\theta}{1 - \tan^2\theta}Double angle formula
265Sine Triple Anglesin⁡3θ=3sin⁡θ−4sin⁡3θ\sin 3\theta = 3\sin\theta - 4\sin^3\thetaTriple angle expansion
266Cosine Triple Anglecos⁡3θ=4cos⁡3θ−3cos⁡θ\cos 3\theta = 4\cos^3\theta - 3\cos\thetaTriple angle expansion
267Tangent Triple Angletan⁡3θ=3tan⁡θ−tan⁡3θ1−3tan⁡2θ\tan 3\theta = \frac{3\tan\theta - \tan^3\theta}{1 - 3\tan^2\theta}Triple angle expansion
268Sine Half Anglesin⁡(θ2)=±1−cos⁡θ2\sin\left(\frac{\theta}{2}\right) = \pm\sqrt{\frac{1 - \cos\theta}{2}}Sign determined by quadrant of θ/2\theta/2
269Cosine Half Anglecos⁡(θ2)=±1+cos⁡θ2\cos\left(\frac{\theta}{2}\right) = \pm\sqrt{\frac{1 + \cos\theta}{2}}Sign determined by quadrant of θ/2\theta/2
270Tangent Half Angletan⁡(θ2)=1−cos⁡θsin⁡θ=sin⁡θ1+cos⁡θ\tan\left(\frac{\theta}{2}\right) = \frac{1 - \cos\theta}{\sin\theta} = \frac{\sin\theta}{1 + \cos\theta}Rational half-angle forms

Product-Sum & Power Reduction Transformations

No.TransformationFormulaConditions / Notes
271Product to Sum: sin⁡sin⁡\sin\sinsin⁡Asin⁡B=12[cos⁡(A−B)−cos⁡(A+B)]\sin A\sin B = \frac{1}{2}[\cos(A - B) - \cos(A + B)]Converts products to sums
272Product to Sum: cos⁡cos⁡\cos\coscos⁡Acos⁡B=12[cos⁡(A−B)+cos⁡(A+B)]\cos A\cos B = \frac{1}{2}[\cos(A - B) + \cos(A + B)]Converts products to sums
273Product to Sum: sin⁡cos⁡\sin\cossin⁡Acos⁡B=12[sin⁡(A+B)+sin⁡(A−B)]\sin A\cos B = \frac{1}{2}[\sin(A + B) + \sin(A - B)]Converts products to sums
274Sum to Product: sin⁡+sin⁡\sin + \sinsin⁡A+sin⁡B=2sin⁡(A+B2)cos⁡(A−B2)\sin A + \sin B = 2\sin\left(\frac{A + B}{2}\right)\cos\left(\frac{A - B}{2}\right)Converts sums to products
275Sum to Product: sin⁡−sin⁡\sin - \sinsin⁡A−sin⁡B=2cos⁡(A+B2)sin⁡(A−B2)\sin A - \sin B = 2\cos\left(\frac{A + B}{2}\right)\sin\left(\frac{A - B}{2}\right)Converts differences to products
276Sum to Product: cos⁡+cos⁡\cos + \coscos⁡A+cos⁡B=2cos⁡(A+B2)cos⁡(A−B2)\cos A + \cos B = 2\cos\left(\frac{A + B}{2}\right)\cos\left(\frac{A - B}{2}\right)Converts sums to products
277Sum to Product: cos⁡−cos⁡\cos - \coscos⁡A−cos⁡B=−2sin⁡(A+B2)sin⁡(A−B2)\cos A - \cos B = -2\sin\left(\frac{A + B}{2}\right)\sin\left(\frac{A - B}{2}\right)Converts differences to products
278Sine Power Reductionsin⁡2θ=1−cos⁡2θ2\sin^2\theta = \frac{1 - \cos 2\theta}{2}Useful in calculus integrations
279Cosine Power Reductioncos⁡2θ=1+cos⁡2θ2\cos^2\theta = \frac{1 + \cos 2\theta}{2}Useful in calculus integrations
280Tangent Power Reductiontan⁡2θ=1−cos⁡2θ1+cos⁡2θ\tan^2\theta = \frac{1 - \cos 2\theta}{1 + \cos 2\theta}Ratio of power reduction forms

22. Inverse Trigonometry

No.Property / IdentityExpressionConditions / Notes
281arcsin⁡x\arcsin x Principal Rangearcsin⁡x∈[−π2,π2]\arcsin x \in \left[-\frac{\pi}{2}, \frac{\pi}{2}\right]Domain: x∈[−1,1]x \in [-1, 1]
282arccos⁡x\arccos x Principal Rangearccos⁡x∈[0,π]\arccos x \in [0, \pi]Domain: x∈[−1,1]x \in [-1, 1]
283arctan⁡x\arctan x Principal Rangearctan⁡x∈(−π2,π2)\arctan x \in \left(-\frac{\pi}{2}, \frac{\pi}{2}\right)Domain: x∈Rx \in \mathbb{R}
284Complementary Arc Sumarcsin⁡x+arccos⁡x=π2\arcsin x + \arccos x = \frac{\pi}{2}Valid for x∈[−1,1]x \in [-1, 1]
285Reciprocal Argument arctan⁡\arctanarctan⁡x+arctan⁡(1x)={π2,x>0−π2,x<0\arctan x + \arctan\left(\frac{1}{x}\right) = \begin{cases} \frac{\pi}{2}, & x > 0 \\ -\frac{\pi}{2}, & x < 0 \end{cases}Reciprocal argument identity
286Addition of arctan⁡\arctanarctan⁡x+arctan⁡y=arctan⁡(x+y1−xy)\arctan x + \arctan y = \arctan\left(\frac{x + y}{1 - xy}\right)For xy<1xy < 1 (quadrant adjustments if xy>1xy > 1)

Complex Numbers

23. Complex Numbers

No.Concept / PropertyFormulaConditions / Notes
287Standard Algebraic Formz=a+biz = a + bia=Re⁡(z),b=Im⁡(z),i2=−1a = \operatorname{Re}(z), b = \operatorname{Im}(z), i^2 = -1
288Powers of ii Cyclei0=1,  i1=i,  i2=−1,  i3=−i,  i4=1i^0=1,\; i^1=i,\; i^2=-1,\; i^3=-i,\; i^4=1Powers repeat with period 4
289Complex Conjugatezˉ=a−bi\bar{z} = a - biReflection across real axis
290Modulus (Absolute Value)∣z∣=a2+b2\vert z\vert = \sqrt{a^2 + b^2}Euclidean distance from origin in complex plane
291Modulus-Conjugate Relationzzˉ=∣z∣2z\bar{z} = \vert z\vert^2Crucial for division / rationalization
292Complex Addition(a+bi)+(c+di)=(a+c)+(b+d)i(a + bi) + (c + di) = (a + c) + (b + d)iAdd real and imaginary parts
293Complex Multiplication(a+bi)(c+di)=(ac−bd)+(ad+bc)i(a + bi)(c + di) = (ac - bd) + (ad + bc)iFOIL expansion with i2=−1i^2 = -1
294Complex Divisiona+bic+di=(a+bi)(c−di)c2+d2\frac{a + bi}{c + di} = \frac{(a + bi)(c - di)}{c^2 + d^2}Multiply numerator & denominator by wˉ\bar{w}
295Polar Trigonometric Formz=r(cos⁡θ+isin⁡θ)z = r(\cos\theta + i\sin\theta)r=∣z∣,θ=arg⁡(z)r = \vert z\vert, \theta = \operatorname{arg}(z)
296Euler’s Formulaeiθ=cos⁡θ+isin⁡θe^{i\theta} = \cos\theta + i\sin\thetaBridges complex exponential and trigonometry
297Exponential Complex Formz=reiθz = r e^{i\theta}Compact polar representation
298De Moivre’s Theorem(cos⁡θ+isin⁡θ)n=cos⁡(nθ)+isin⁡(nθ)(\cos\theta + i\sin\theta)^n = \cos(n\theta) + i\sin(n\theta)(eiθ)n=einθ(e^{i\theta})^n = e^{in\theta} for n∈Zn \in \mathbb{Z}
299nn-th Roots of Complex Numberzk=r1/neiθ+2kπnz_k = r^{1/n} e^{i\frac{\theta + 2k\pi}{n}}k=0,1,…,n−1k = 0, 1, \ldots, n-1 (equally spaced roots)
300Euler’s Identityeiπ+1=0e^{i\pi} + 1 = 0Fundamental identity linking 5 core constants

Differentiation

24. Limits

No.Limit Law / Standard LimitFormulaConditions / Notes
301Derivative Definition Limitf′(x)=lim⁡h→0f(x+h)−f(x)hf'(x) = \lim_{h \to 0} \frac{f(x + h) - f(x)}{h}Instantaneous rate of change
302Fundamental Trig Limit Ilim⁡x→0sin⁡xx=1\lim_{x \to 0} \frac{\sin x}{x} = 1Angle xx measured in radians
303Fundamental Trig Limit IIlim⁡x→0tan⁡xx=1\lim_{x \to 0} \frac{\tan x}{x} = 1Angle xx measured in radians
304Cosine Limitlim⁡x→01−cos⁡xx2=12\lim_{x \to 0} \frac{1 - \cos x}{x^2} = \frac{1}{2}Derived via half-angle identity
305Exponential Limitlim⁡x→0ex−1x=1\lim_{x \to 0} \frac{e^x - 1}{x} = 1Derivative of exe^x at x=0x=0
306Logarithmic Limitlim⁡x→0ln⁡(1+x)x=1\lim_{x \to 0} \frac{\ln(1 + x)}{x} = 1Derivative of ln⁡x\ln x at x=1x=1
307Euler’s Number Limitlim⁡x→∞(1+1x)x=e\lim_{x \to \infty} \left(1 + \frac{1}{x}\right)^x = eContinuous compounding base
308Generalized Euler Limitlim⁡x→∞(1+ax)x=ea\lim_{x \to \infty} \left(1 + \frac{a}{x}\right)^x = e^aExponential power limit
309Sum & Product Lawslim⁡(f±g)=lim⁡f±lim⁡g,  lim⁡(fg)=(lim⁡f)(lim⁡g)\lim(f \pm g) = \lim f \pm \lim g,\; \lim(fg) = (\lim f)(\lim g)Provided limits exist independently
310Quotient Lawlim⁡fg=lim⁡flim⁡g\lim \frac{f}{g} = \frac{\lim f}{\lim g}Valid when lim⁡g≠0\lim g \ne 0

25. Differentiation

Basic & Core Differentiation Rules

No.RuleFormulaConditions / Notes
311Constant Ruleddx(c)=0\frac{d}{dx}(c) = 0Derivative of constant is zero
312Power Ruleddx(xn)=nxn−1\frac{d}{dx}(x^n) = n x^{n-1}Valid for all real powers nn
313Constant Multiple Ruleddx[cf(x)]=cf′(x)\frac{d}{dx}[c f(x)] = c f'(x)Scalar factors out of derivative
314Sum and Difference Ruleddx[f(x)±g(x)]=f′(x)±g′(x)\frac{d}{dx}[f(x) \pm g(x)] = f'(x) \pm g'(x)Linearity of derivative operator
315Product Ruleddx[fg]=f′g+fg′\frac{d}{dx}[f g] = f' g + f g'Leibniz product rule
316Quotient Ruleddx[fg]=f′g−fg′g2\frac{d}{dx}\left[\frac{f}{g}\right] = \frac{f' g - f g'}{g^2}Valid where g(x)≠0g(x) \ne 0
317Chain Rule (Function Form)ddx[f(g(x))]=f′(g(x))g′(x)\frac{d}{dx}[f(g(x))] = f'(g(x)) g'(x)Derivative of composite functions
318Chain Rule (Leibniz Form)dydx=dydududx\frac{dy}{dx} = \frac{dy}{du}\frac{du}{dx}Chain rule with intermediate variable uu

Derivatives of Elementary Functions

No.FunctionDerivativeConditions / Notes
319Natural Exponentialddx(ex)=ex\frac{d}{dx}(e^x) = e^xEigenfunction of differentiation
320Composite Exponentialddx(eu)=euu′\frac{d}{dx}(e^u) = e^u u'Chain rule form (u=u(x)u = u(x))
321General Exponentialddx(ax)=axln⁡a\frac{d}{dx}(a^x) = a^x \ln aa>0,a≠1a > 0, a \ne 1
322Natural Logarithmddx(ln⁡x)=1x\frac{d}{dx}(\ln x) = \frac{1}{x}x>0x > 0
323General Logarithmddx(log⁡ax)=1xln⁡a\frac{d}{dx}(\log_a x) = \frac{1}{x \ln a}a>0,a≠1,x>0a > 0, a \ne 1, x > 0
324Sine Derivativeddx(sin⁡x)=cos⁡x\frac{d}{dx}(\sin x) = \cos xRadians required
325Cosine Derivativeddx(cos⁡x)=−sin⁡x\frac{d}{dx}(\cos x) = -\sin xRadians required
326Tangent Derivativeddx(tan⁡x)=sec⁡2x\frac{d}{dx}(\tan x) = \sec^2 xRadians required
327Cotangent Derivativeddx(cot⁡x)=−csc⁡2x\frac{d}{dx}(\cot x) = -\csc^2 xRadians required
328Secant Derivativeddx(sec⁡x)=sec⁡xtan⁡x\frac{d}{dx}(\sec x) = \sec x\tan xRadians required
329Cosecant Derivativeddx(csc⁡x)=−csc⁡xcot⁡x\frac{d}{dx}(\csc x) = -\csc x\cot xRadians required
330Inverse Sine Derivativeddx(arcsin⁡x)=11−x2\frac{d}{dx}(\arcsin x) = \frac{1}{\sqrt{1 - x^2}}∣x∣<1\vert x\vert < 1
331Inverse Cosine Derivativeddx(arccos⁡x)=−11−x2\frac{d}{dx}(\arccos x) = -\frac{1}{\sqrt{1 - x^2}}∣x∣<1\vert x\vert < 1
332Inverse Tangent Derivativeddx(arctan⁡x)=11+x2\frac{d}{dx}(\arctan x) = \frac{1}{1 + x^2}Valid for all x∈Rx \in \mathbb{R}
333Hyperbolic Sineddx(sinh⁡x)=cosh⁡x\frac{d}{dx}(\sinh x) = \cosh xsinh⁡x=ex−e−x2\sinh x = \frac{e^x - e^{-x}}{2}
334Hyperbolic Cosineddx(cosh⁡x)=sinh⁡x\frac{d}{dx}(\cosh x) = \sinh xcosh⁡x=ex+e−x2\cosh x = \frac{e^x + e^{-x}}{2}
335Hyperbolic Tangentddx(tanh⁡x)=sech⁡2x\frac{d}{dx}(\tanh x) = \operatorname{sech}^2 xtanh⁡x=sinh⁡xcosh⁡x\tanh x = \frac{\sinh x}{\cosh x}

26. Applications of Differentiation

No.Application / ConceptFormula / RuleConditions / Notes
336Tangent Line Equationy−f(a)=f′(a)(x−a)y - f(a) = f'(a)(x - a)Point-slope line with derivative as slope
337Normal Line Equationy−f(a)=−1f′(a)(x−a)y - f(a) = -\frac{1}{f'(a)}(x - a)Perpendicular to tangent (f′(a)≠0f'(a) \ne 0)
338Critical Point Conditionf′(x)=0 or f′(x) undefinedf'(x) = 0 \text{ or } f'(x) \text{ undefined}Candidates for local extrema
339Second Derivative Test (Min)f′(c)=0 and f′′(c)>0  ⟹  Local Minf'(c) = 0 \text{ and } f''(c) > 0 \implies \text{Local Min}Graph concave up at cc
340Second Derivative Test (Max)f′(c)=0 and f′′(c)<0  ⟹  Local Maxf'(c) = 0 \text{ and } f''(c) < 0 \implies \text{Local Max}Graph concave down at cc
341Monotonicity Testf′(x)>0  ⟹  Increasing,  f′(x)<0  ⟹  Decreasingf'(x) > 0 \implies \text{Increasing},\; f'(x) < 0 \implies \text{Decreasing}Over open interval II
342Concavity Testf′′(x)>0  ⟹  Concave Up,  f′′(x)<0  ⟹  Concave Downf''(x) > 0 \implies \text{Concave Up},\; f''(x) < 0 \implies \text{Concave Down}Over open interval II
343Linear Approximationf(x)≈f(a)+f′(a)(x−a)f(x) \approx f(a) + f'(a)(x - a)First-order Taylor polynomial near aa
344Mean Value Theorem (MVT)f′(c)=f(b)−f(a)b−af'(c) = \frac{f(b) - f(a)}{b - a}Continuous on [a,b][a, b], differentiable on (a,b)(a, b)
345Rolle’s Theoremf(a)=f(b)  ⟹  ∃c∈(a,b):f′(c)=0f(a) = f(b) \implies \exists c \in (a, b): f'(c) = 0Special case of MVT with equal endpoints

Integration

27. Integration

Indefinite Integrals & Core Techniques

No.Rule / FormFormulaConditions / Notes
346Constant Rule∫c dx=cx+C\int c\,dx = cx + Ccc is constant, CC is integration constant
347Power Rule of Integration∫xn dx=xn+1n+1+C\int x^n\,dx = \frac{x^{n+1}}{n+1} + CValid for all n≠−1n \ne -1
348Reciprocal Integral∫1x dx=ln⁡∣x∣+C\int \frac{1}{x}\,dx = \ln\vert x\vert + Cx≠0x \ne 0
349Exponential Integral∫ex dx=ex+C\int e^x\,dx = e^x + CNatural base exponential
350General Exponential Integral∫ax dx=axln⁡a+C\int a^x\,dx = \frac{a^x}{\ln a} + Ca>0,a≠1a > 0, a \ne 1
351Linearity of Integration∫[af(x)+bg(x)]dx=a∫f(x)dx+b∫g(x)dx\int [a f(x) + b g(x)]dx = a\int f(x)dx + b\int g(x)dxLinear operator property
352Integration by Substitution∫f(g(x))g′(x) dx=∫f(u) du\int f(g(x))g'(x)\,dx = \int f(u)\,duu=g(x),du=g′(x)dxu = g(x), du = g'(x)dx
353Integration by Parts∫u dv=uv−∫v du\int u\,dv = uv - \int v\,duDerived from product rule

Trigonometric & Special Integrals

No.IntegrandAntiderivativeConditions / Notes
354Sine Integral∫sin⁡x dx=−cos⁡x+C\int \sin x\,dx = -\cos x + CAntiderivative of sine
355Cosine Integral∫cos⁡x dx=sin⁡x+C\int \cos x\,dx = \sin x + CAntiderivative of cosine
356Tangent Integral∫tan⁡x dx=−ln⁡∣cos⁡x∣+C=ln⁡∣sec⁡x∣+C\int \tan x\,dx = -\ln\vert\cos x\vert + C = \ln\vert\sec x\vert + CIntegrable via substitution
357Cotangent Integral∫cot⁡x dx=ln⁡∣sin⁡x∣+C\int \cot x\,dx = \ln\vert\sin x\vert + CIntegrable via substitution
358Secant Squared Integral∫sec⁡2x dx=tan⁡x+C\int \sec^2 x\,dx = \tan x + CStandard derivative inverse
359Cosecant Squared Integral∫csc⁡2x dx=−cot⁡x+C\int \csc^2 x\,dx = -\cot x + CStandard derivative inverse
360Secant-Tangent Integral∫sec⁡xtan⁡x dx=sec⁡x+C\int \sec x\tan x\,dx = \sec x + CStandard derivative inverse
361Cosecant-Cotangent Integral∫csc⁡xcot⁡x dx=−csc⁡x+C\int \csc x\cot x\,dx = -\csc x + CStandard derivative inverse
362Inverse Tangent Form∫1a2+x2 dx=1aarctan⁡(xa)+C\int \frac{1}{a^2 + x^2}\,dx = \frac{1}{a}\arctan\left(\frac{x}{a}\right) + Ca>0a > 0
363Inverse Sine Form∫1a2−x2 dx=arcsin⁡(xa)+C\int \frac{1}{\sqrt{a^2 - x^2}}\,dx = \arcsin\left(\frac{x}{a}\right) + Ca>0,∣x∣<aa > 0, \vert x\vert < a
364Fundamental Theorem of Calculus (I)ddx∫axf(t) dt=f(x)\frac{d}{dx}\int_a^x f(t)\,dt = f(x)Differentiation of integral function
365Fundamental Theorem of Calculus (II)∫abf(x) dx=F(b)−F(a)\int_a^b f(x)\,dx = F(b) - F(a)F′(x)=f(x)F'(x) = f(x) on [a,b][a, b]

28. Applications of Integration

No.ApplicationFormulaConditions / Notes
366Area Under CurveA=∫abf(x) dxA = \int_a^b f(x)\,dxFor f(x)≥0f(x) \ge 0 on [a,b][a, b]
367Area Between Curves (xx-slices)A=∫ab[f(x)−g(x)] dxA = \int_a^b [f(x) - g(x)]\,dxf(x)≥g(x)f(x) \ge g(x) (upper minus lower)
368Area Between Curves (yy-slices)A=∫cd[f(y)−g(y)] dyA = \int_c^d [f(y) - g(y)]\,dyf(y)≥g(y)f(y) \ge g(y) (right minus left)
369Solid of Revolution: Disk MethodV=π∫ab[f(x)]2 dxV = \pi\int_a^b [f(x)]^2\,dxRotation around the xx-axis
370Solid of Revolution: Washer MethodV=π∫ab[R(x)2−r(x)2] dxV = \pi\int_a^b [R(x)^2 - r(x)^2]\,dxOuter radius R(x)R(x), inner radius r(x)r(x)
371Solid of Revolution: Shell MethodV=2π∫abxf(x) dxV = 2\pi\int_a^b x f(x)\,dxRotation around the yy-axis (x≥0x \ge 0)
372Arc Length (y=f(x)y = f(x))L=∫ab1+[f′(x)]2 dxL = \int_a^b \sqrt{1 + [f'(x)]^2}\,dxCurve length along xx-interval [a,b][a, b]
373Arc Length (x=g(y)x = g(y))L=∫cd1+[g′(y)]2 dyL = \int_c^d \sqrt{1 + [g'(y)]^2}\,dyCurve length along yy-interval [c,d][c, d]
374Surface Area of RevolutionS=2π∫abf(x)1+[f′(x)]2 dxS = 2\pi\int_a^b f(x)\sqrt{1 + [f'(x)]^2}\,dxRotation of y=f(x)y=f(x) around xx-axis
375Average Value of Functionfavg=1b−a∫abf(x) dxf_{\text{avg}} = \frac{1}{b - a}\int_a^b f(x)\,dxMean height of function over [a,b][a, b]

29. Differential Equations

No.ODE TypeForm & SolutionConditions / Notes
376Separable ODEdydx=g(x)h(y)  ⟹  ∫dyh(y)=∫g(x) dx\frac{dy}{dx} = g(x)h(y) \implies \int \frac{dy}{h(y)} = \int g(x)\,dxSeparate variables and integrate both sides
377First-Order Linear ODEdydx+P(x)y=Q(x)\frac{dy}{dx} + P(x)y = Q(x)Standard linear differential equation
378Integrating FactorIF=e∫P(x) dxIF = e^{\int P(x)\,dx}Factor converting LHS into product derivative
379First-Order Linear Solutiony⋅IF=∫Q(x)IF dx+Cy \cdot IF = \int Q(x)IF\,dx + CGeneral solution via integrating factor
380Exponential Growth / Decaydydt=ky  ⟹  y(t)=y0ekt\frac{dy}{dt} = ky \implies y(t) = y_0 e^{kt}k>0k > 0 growth, k<0k < 0 decay
381Radioactive Half-Lifet1/2=ln⁡2∣k∣t_{1/2} = \frac{\ln 2}{\vert k\vert}Time required for half of substance to decay
382Logistic Differential EquationdPdt=rP(1−PK)\frac{dP}{dt} = rP\left(1 - \frac{P}{K}\right)Carrying capacity KK, intrinsic growth rate rr
383Logistic Analytical SolutionP(t)=K1+Ae−rt,  A=K−P0P0P(t) = \frac{K}{1 + A e^{-rt}},\; A = \frac{K - P_0}{P_0}S-shaped sigmoidal population curve
384Second-Order Homogeneous ODEay′′+by′+cy=0a y'' + b y' + c y = 0Constant coefficients a,b,ca, b, c
385Characteristic Equationar2+br+c=0a r^2 + b r + c = 0Quadratic auxiliary equation in rr

Vectors & Matrices

30. Vectors

No.Vector Concept / OperationFormulaConditions / Notes
3863D Component Representationv⃗=⟨v1,v2,v3⟩=v1i+v2j+v3k\vec{v} = \langle v_1, v_2, v_3\rangle = v_1\mathbf{i} + v_2\mathbf{j} + v_3\mathbf{k}Cartesian vector components
387Vector Magnitude∣v⃗∣=v12+v22+v32\vert\vec{v}\vert = \sqrt{v_1^2 + v_2^2 + v_3^2}Euclidean length / norm
388Unit Vectorv^=v⃗∣v⃗∣\hat{v} = \frac{\vec{v}}{\vert\vec{v}\vert}Normalization of nonzero vector v⃗\vec{v}
389Vector Additiona⃗+b⃗=⟨a1+b1,a2+b2,a3+b3⟩\vec{a} + \vec{b} = \langle a_1 + b_1, a_2 + b_2, a_3 + b_3\rangleComponent-wise addition
390Dot Product (Algebraic)a⃗⋅b⃗=a1b1+a2b2+a3b3\vec{a} \cdot \vec{b} = a_1 b_1 + a_2 b_2 + a_3 b_3Scalar result
391Dot Product (Geometric)a⃗⋅b⃗=∣a⃗∣∣b⃗∣cos⁡θ\vec{a} \cdot \vec{b} = \vert\vec{a}\vert \vert\vec{b}\vert\cos\thetaθ\theta is angle between vectors
392Angle Between Vectorscos⁡θ=a⃗⋅b⃗∣a⃗∣∣b⃗∣\cos\theta = \frac{\vec{a} \cdot \vec{b}}{\vert\vec{a}\vert \vert\vec{b}\vert}Orthogonal iff a⃗⋅b⃗=0\vec{a} \cdot \vec{b} = 0
393Cross Product Formulaa⃗×b⃗=∣ijka1a2a3b1b2b3∣\vec{a} \times \vec{b} = \begin{vmatrix} \mathbf{i} & \mathbf{j} & \mathbf{k} \\ a_1 & a_2 & a_3 \\ b_1 & b_2 & b_3 \end{vmatrix}Vector perpendicular to both a⃗\vec{a} and b⃗\vec{b}
394Cross Product Magnitude∣a⃗×b⃗∣=∣a⃗∣∣b⃗∣sin⁡θ\vert\vec{a} \times \vec{b}\vert = \vert\vec{a}\vert \vert\vec{b}\vert\sin\thetaParallel iff a⃗×b⃗=0⃗\vec{a} \times \vec{b} = \vec{0}
395Scalar Projectioncomp⁡b⃗a⃗=a⃗⋅b⃗∣b⃗∣\operatorname{comp}_{\vec{b}}\vec{a} = \frac{\vec{a} \cdot \vec{b}}{\vert\vec{b}\vert}Component of a⃗\vec{a} along b⃗\vec{b}
396Vector Projectionproj⁡b⃗a⃗=(a⃗⋅b⃗∣b⃗∣2)b⃗\operatorname{proj}_{\vec{b}}\vec{a} = \left(\frac{\vec{a} \cdot \vec{b}}{\vert\vec{b}\vert^2}\right)\vec{b}Vector projected onto direction of b⃗\vec{b}
397Parallelogram AreaA=∣a⃗×b⃗∣A = \vert\vec{a} \times \vec{b}\vertArea spanned by vectors a⃗\vec{a} and b⃗\vec{b}
398Triangle Area from VectorsA=12∣a⃗×b⃗∣A = \frac{1}{2}\vert\vec{a} \times \vec{b}\vertHalf of parallelogram area
399Scalar Triple Producta⃗⋅(b⃗×c⃗)=∣a1a2a3b1b2b3c1c2c3∣\vec{a} \cdot (\vec{b} \times \vec{c}) = \begin{vmatrix} a_1 & a_2 & a_3 \\ b_1 & b_2 & b_3 \\ c_1 & c_2 & c_3 \end{vmatrix}Volume of parallelepiped =∣a⃗⋅(b⃗×c⃗)∣= \vert\vec{a} \cdot (\vec{b} \times \vec{c})\vert

31. Matrices

No.Operation / PropertyFormulaConditions / Notes
400Matrix Addition(A+B)ij=aij+bij(A + B)_{ij} = a_{ij} + b_{ij}Matrices must share identical dimensions
401Scalar Multiplication(cA)ij=caij(c A)_{ij} = c a_{ij}Multiplies every entry by scalar cc
402Matrix Multiplication(AB)ij=∑k=1naikbkj(A B)_{ij} = \sum_{k=1}^n a_{ik} b_{kj}AA is m×nm\times n, BB is n×pn\times p; generally AB≠BAAB \ne BA
403Matrix Transpose(AT)ij=aji(A^T)_{ij} = a_{ji}Swaps rows and columns
404Transpose of Product(AB)T=BTAT(AB)^T = B^T A^TReverses order of matrix product
405Inverse of 2×22\times 2 Matrix(abcd)−1=1ad−bc(d−b−ca)\begin{pmatrix} a & b \\ c & d \end{pmatrix}^{-1} = \frac{1}{ad - bc}\begin{pmatrix} d & -b \\ -c & a \end{pmatrix}Invertible iff det⁡A=ad−bc≠0\det A = ad - bc \ne 0
406General Matrix InverseA−1=adj⁡(A)det⁡AA^{-1} = \frac{\operatorname{adj}(A)}{\det A}Invertible iff det⁡A≠0\det A \ne 0
407Matrix Tracetr⁡(A)=∑i=1naii\operatorname{tr}(A) = \sum_{i=1}^n a_{ii}Sum of main diagonal elements
408Eigenvalue EquationAv⃗=λv⃗  ⟺  det⁡(A−λI)=0A\vec{v} = \lambda\vec{v} \iff \det(A - \lambda I) = 0Characteristic equation determines eigenvalues λ\lambda
409Characteristic Polynomial (2×22\times 2)λ2−tr⁡(A)λ+det⁡(A)=0\lambda^2 - \operatorname{tr}(A)\lambda + \det(A) = 0Characteristic equation for 2×22\times 2 matrices

32. Determinants

No.Concept / PropertyFormulaConditions / Notes
4102×22\times 2 Determinant∣abcd∣=ad−bc\begin{vmatrix} a & b \\ c & d \end{vmatrix} = ad - bcProduct of main diag minus anti-diag
4113×33\times 3 Determinant∣abcdefghi∣=a(ei−fh)−b(di−fg)+c(dh−eg)\begin{vmatrix} a & b & c \\ d & e & f \\ g & h & i \end{vmatrix} = a(ei - fh) - b(di - fg) + c(dh - eg)Cofactor expansion along first row
412Multiplicative Propertydet⁡(AB)=det⁡(A)det⁡(B)\det(AB) = \det(A)\det(B)Determinant of matrix product
413Transpose Propertydet⁡(AT)=det⁡(A)\det(A^T) = \det(A)Transpose preserves determinant
414Inverse Propertydet⁡(A−1)=1det⁡(A)\det(A^{-1}) = \frac{1}{\det(A)}Reciprocal of determinant
415Row Multiplication by Scalardet⁡(A′)=kdet⁡(A)\det(A') = k\det(A)Multiplying a single row by kk
416Triangular Matrix Determinantdet⁡A=∏i=1naii\det A = \prod_{i=1}^n a_{ii}Product of diagonal entries for triangular matrices

Probability & Statistics

33. Probability

No.Rule / TheoremFormulaConditions / Notes
417Classical ProbabilityP(A)=Favorable OutcomesTotal Possible OutcomesP(A) = \frac{\text{Favorable Outcomes}}{\text{Total Possible Outcomes}}Equally likely outcome space
418Complement RuleP(Ac)=1−P(A)P(A^c) = 1 - P(A)Probability of event not occurring
419Addition Rule (General)P(A∪B)=P(A)+P(B)−P(A∩B)P(A \cup B) = P(A) + P(B) - P(A \cap B)Union of any two events
420Addition Rule (Mutually Exclusive)P(A∪B)=P(A)+P(B)P(A \cup B) = P(A) + P(B)When A∩B=∅A \cap B = \emptyset
421Conditional ProbabilityP(A∣B)=P(A∩B)P(B)P(A\mid B) = \frac{P(A \cap B)}{P(B)}Probability of AA given BB occurred (P(B)>0P(B) > 0)
422Multiplication RuleP(A∩B)=P(A∣B)P(B)=P(B∣A)P(A)P(A \cap B) = P(A\mid B)P(B) = P(B\mid A)P(A)Joint probability calculation
423Independent EventsP(A∩B)=P(A)P(B)  ⟺  P(A∣B)=P(A)P(A \cap B) = P(A)P(B) \iff P(A\mid B) = P(A)Events exert no mutual influence
424Bayes’ TheoremP(A∣B)=P(B∣A)P(A)P(B)P(A\mid B) = \frac{P(B\mid A)P(A)}{P(B)}Posterior probability from likelihood and prior
425Law of Total ProbabilityP(B)=∑iP(B∣Ai)P(Ai)P(B) = \sum_{i} P(B\mid A_i)P(A_i)For partition {A1,A2,…,An}\{A_1, A_2, \ldots, A_n\}

34. Statistics

No.Statistical MeasureFormulaConditions / Notes
426Arithmetic Mean (Sample)xˉ=1n∑i=1nxi\bar{x} = \frac{1}{n}\sum_{i=1}^n x_iSum divided by sample size nn
427Weighted Meanxˉw=∑wixi∑wi\bar{x}_w = \frac{\sum w_i x_i}{\sum w_i}Accounts for varying observations weights wiw_i
428RangeRange=xmax⁡−xmin⁡\text{Range} = x_{\max} - x_{\min}Difference between extreme values
429Population Varianceσ2=1N∑i=1N(xi−μ)2\sigma^2 = \frac{1}{N}\sum_{i=1}^N (x_i - \mu)^2For entire population of size NN
430Population Standard Deviationσ=1N∑i=1N(xi−μ)2\sigma = \sqrt{\frac{1}{N}\sum_{i=1}^N (x_i - \mu)^2}Square root of population variance
431Sample Variances2=1n−1∑i=1n(xi−xˉ)2s^2 = \frac{1}{n - 1}\sum_{i=1}^n (x_i - \bar{x})^2Bessel’s correction with n−1n-1 degrees of freedom
432Sample Standard Deviations=1n−1∑i=1n(xi−xˉ)2s = \sqrt{\frac{1}{n - 1}\sum_{i=1}^n (x_i - \bar{x})^2}Sample variability metric
433Variance Computational Shortcuts2=1n−1[∑xi2−(∑xi)2n]s^2 = \frac{1}{n - 1}\left[\sum x_i^2 - \frac{(\sum x_i)^2}{n}\right]Single-pass calculation formula
434Coefficient of VariationCV=σμ×100%CV = \frac{\sigma}{\mu} \times 100\%Relative dispersion metric
435Standard Score (ZZ-Score)Z=x−μσZ = \frac{x - \mu}{\sigma}Number of standard deviations from mean
436Sample Covariancesxy=1n−1∑(xi−xˉ)(yi−yˉ)s_{xy} = \frac{1}{n - 1}\sum (x_i - \bar{x})(y_i - \bar{y})Joint variability of two variables
437Pearson Correlation (rr)r=sxysxsy=∑(xi−xˉ)(yi−yˉ)∑(xi−xˉ)2∑(yi−yˉ)2r = \frac{s_{xy}}{s_x s_y} = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sqrt{\sum (x_i - \bar{x})^2 \sum (y_i - \bar{y})^2}}Linear association (−1≤r≤1-1 \le r \le 1)
438Regression Line Slopem=n∑xy−∑x∑yn∑x2−(∑x)2=rsysxm = \frac{n\sum xy - \sum x\sum y}{n\sum x^2 - (\sum x)^2} = r\frac{s_y}{s_x}Slope of least-squares line y=mx+cy = mx + c
439Regression Line Interceptc=yˉ−mxˉc = \bar{y} - m\bar{x}yy-intercept of least-squares regression line

Discrete Mathematics & Number Theory

35. Discrete Mathematics

No.Logical Law / PrincipleEquivalence / FormulaConditions / Notes
440Conditional (Implication)p→q≡¬p∨qp \to q \equiv \neg p \lor qFundamental implication identity
441Contrapositive Lawp→q≡¬q→¬pp \to q \equiv \neg q \to \neg pLogically identical to conditional
442Biconditional Lawp↔q≡(p→q)∧(q→p)p \leftrightarrow q \equiv (p \to q) \land (q \to p)Mutual implication equivalence
443De Morgan’s Law (AND)¬(p∧q)≡¬p∨¬q\neg(p \land q) \equiv \neg p \lor \neg qNegation of conjunction
444De Morgan’s Law (OR)¬(p∨q)≡¬p∧¬q\neg(p \lor q) \equiv \neg p \land \neg qNegation of disjunction
445Double Negation¬(¬p)≡p\neg(\neg p) \equiv pInvolution property
446Idempotent Lawsp∨p≡p and p∧p≡pp \lor p \equiv p \text{ and } p \land p \equiv pSelf-combination yields same statement
447Identity Lawsp∨F≡p and p∧T≡pp \lor F \equiv p \text{ and } p \land T \equiv pNeutral truth elements
448Domination Lawsp∨T≡T and p∧F≡Fp \lor T \equiv T \text{ and } p \land F \equiv FAnnihilating truth elements
449Complement Lawsp∨¬p≡T and p∧¬p≡Fp \lor \neg p \equiv T \text{ and } p \land \neg p \equiv FLaw of excluded middle and non-contradiction

36. Number Theory

No.Concept / TheoremFormula / PropertyConditions / Notes
450Divisibility Definitiona∣b  ⟺  b=aka \mid b \iff b = akFor some integer kk
451Euclidean Algorithmgcd⁡(a,b)=gcd⁡(b,a mod b)\gcd(a, b) = \gcd(b, a \bmod b)Iterated reduction until remainder is zero
452LCM-GCD Product Relationlcm⁡(a,b)⋅gcd⁡(a,b)=ab\operatorname{lcm}(a, b) \cdot \gcd(a, b) = a bPositive integers a,ba, b
453Bézout’s Identityax+by=gcd⁡(a,b)a x + b y = \gcd(a, b)Always solvable for integer coefficients x,yx, y
454Congruence Additiona≡b(modm)  ⟹  a+c≡b+c(modm)a \equiv b \pmod m \implies a + c \equiv b + c \pmod mPreserves arithmetic under addition
455Congruence Multiplicationa≡b(modm)  ⟹  ac≡bc(modm)a \equiv b \pmod m \implies ac \equiv bc \pmod mPreserves arithmetic under multiplication
456Modular Multiplicative Inverseax≡1(modm)a x \equiv 1 \pmod mUnique solution exists iff gcd⁡(a,m)=1\gcd(a, m) = 1
457Fermat’s Little Theoremap−1≡1(modp)a^{p-1} \equiv 1 \pmod pPrime pp and gcd⁡(a,p)=1\gcd(a, p) = 1
458Euler’s Totient Productϕ(n)=n∏p∣n(1−1p)\phi(n) = n\prod_{p \mid n}\left(1 - \frac{1}{p}\right)Count of integers 1≤k≤n1 \le k \le n coprime to nn
459Euler’s Theoremaϕ(n)≡1(modn)a^{\phi(n)} \equiv 1 \pmod nGeneralization of FLT for gcd⁡(a,n)=1\gcd(a, n) = 1
460Prime Factorizationn=p1a1p2a2⋯pkakn = p_1^{a_1} p_2^{a_2} \cdots p_k^{a_k}Unique prime factorization of nn
461Number of Divisors d(n)d(n)d(n)=(a1+1)(a2+1)⋯(ak+1)d(n) = (a_1 + 1)(a_2 + 1)\cdots(a_k + 1)Total positive factors
462Sum of Divisors σ(n)\sigma(n)σ(n)=∏i=1kpiai+1−1pi−1\sigma(n) = \prod_{i=1}^k \frac{p_i^{a_i + 1} - 1}{p_i - 1}Total sum of all positive divisors

37. Graph Theory

No.Theorem / PropertyFormulaConditions / Notes
463Handshaking Lemma∑v∈Vdeg⁡(v)=2∣E∣\sum_{v \in V} \deg(v) = 2\vert E\vertEvery edge contributes to two endpoint degrees
464Odd Degree Vertex Count∣{v:deg⁡(v) is odd}∣ is even\vert\{v : \deg(v) \text{ is odd}\}\vert \text{ is even}Consequence of Handshaking Lemma
465Complete Graph Edges∣E(Kn)∣=n(n−1)2\vert E(K_n)\vert = \frac{n(n - 1)}{2}Graph where every pair of vertices is connected
466Complete Bipartite Edges∣E(Km,n)∣=mn\vert E(K_{m, n})\vert = mnPartitions of sizes mm and nn
467Tree Edge Count∣E∣=n−1\vert E\vert = n - 1Connected acyclic graph with nn vertices
468Forest Edge Count∣E∣=n−c\vert E\vert = n - cAcyclic graph with cc connected components
469Euler’s Planar FormulaV−E+F=2V - E + F = 2Connected planar graph with faces FF
470Planar Edge Upper BoundE≤3V−6E \le 3V - 6For simple planar graphs with V≥3V \ge 3

38. Set/Counting/Combinatorial Identities

No.Identity NameFormulaConditions / Notes
471Binomial Sum Identity∑k=0n(nk)=2n\sum_{k=0}^n \binom{n}{k} = 2^nTotal subsets of an nn-element set
472Alternating Binomial Sum∑k=0n(−1)k(nk)=0\sum_{k=0}^n (-1)^k \binom{n}{k} = 0Valid for n>0n > 0
473Weighted Binomial Sum∑k=0nk(nk)=n2n−1\sum_{k=0}^n k \binom{n}{k} = n 2^{n-1}Evaluated via derivative of (1+x)n(1 + x)^n
474Vandermonde’s Identity∑k(rk)(sn−k)=(r+sn)\sum_k \binom{r}{k} \binom{s}{n - k} = \binom{r + s}{n}Convolution of binomial coefficients
475Hockey-Stick Identity∑k=rn(kr)=(n+1r+1)\sum_{k=r}^n \binom{k}{r} = \binom{n + 1}{r + 1}Sum of diagonal entries in Pascal’s triangle
476Catalan Number FormulaCn=1n+1(2nn)C_n = \frac{1}{n + 1}\binom{2n}{n}Sequence: 1, 1, 2, 5, 14, 42, 132…
477Catalan RecurrenceCn+1=2(2n+1)n+2CnC_{n+1} = \frac{2(2n + 1)}{n + 2}C_nMultiplicative growth recurrence

39. Financial Mathematics

No.Financial MetricFormulaConditions / Notes
478Simple InterestSI=PRT100SI = \frac{P R T}{100}Principal PP, rate R%R\%, time TT years
479Simple Total AmountA=P+SI=P(1+RT100)A = P + SI = P\left(1 + \frac{RT}{100}\right)Total accumulated balance
480Compound Interest AmountA=P(1+rn)ntA = P\left(1 + \frac{r}{n}\right)^{nt}Compounded nn times/year at decimal rate rr
481Continuous CompoundingA=PertA = P e^{rt}Limit as compounding frequency n→∞n \to \infty
482Exponential DepreciationV(t)=P(1−r)tV(t) = P(1 - r)^tValue with annual depreciation rate rr
483Present ValuePV=FV(1+r)nPV = \frac{FV}{(1 + r)^n}Discounted current worth of future cash flow
484Future ValueFV=PV(1+r)nFV = PV(1 + r)^nCompounded future worth of present balance
485Annuity Future ValueFV=PMT⋅(1+r)n−1rFV = PMT \cdot \frac{(1 + r)^n - 1}{r}Ordinary annuity with periodic deposit PMTPMT
486Annuity Present ValuePV=PMT⋅1−(1+r)−nrPV = PMT \cdot \frac{1 - (1 + r)^{-n}}{r}Capitalized value of future income stream
487Loan Periodic PaymentPMT=PV⋅r(1+r)n(1+r)n−1PMT = PV \cdot \frac{r(1 + r)^n}{(1 + r)^n - 1}Amortization periodic payment formula

Applied Mathematics & Numerical Methods

40. Numerical Methods

No.MethodIteration / Quadrature FormulaConditions / Notes
488Bisection Method Midpointc=a+b2c = \frac{a + b}{2}Requires f(a)f(b)<0f(a)f(b) < 0
489Newton-Raphson Iterationxn+1=xn−f(xn)f′(xn)x_{n+1} = x_n - \frac{f(x_n)}{f'(x_n)}Quadratic convergence near simple roots
490Secant Method Iterationxn+1=xn−f(xn)xn−xn−1f(xn)−f(xn−1)x_{n+1} = x_n - f(x_n)\frac{x_n - x_{n-1}}{f(x_n) - f(x_{n-1})}Derivative-free approximation
491Single Trapezoidal Rule∫abf(x) dx≈b−a2[f(a)+f(b)]\int_a^b f(x)\,dx \approx \frac{b - a}{2}[f(a) + f(b)]Linear approximation of area
492Composite Trapezoidal Rule∫abf(x) dx≈h2[f(x0)+f(xn)+2∑i=1n−1f(xi)]\int_a^b f(x)\,dx \approx \frac{h}{2}\left[f(x_0) + f(x_n) + 2\sum_{i=1}^{n-1} f(x_i)\right]h=b−anh = \frac{b - a}{n}
493Simpson’s 1/31/3 Rule∫abf(x) dx≈h3[f(x0)+4∑i oddf(xi)+2∑j evenf(xj)+f(xn)]\int_a^b f(x)\,dx \approx \frac{h}{3}\left[f(x_0) + 4\sum_{i \text{ odd}} f(x_i) + 2\sum_{j \text{ even}} f(x_j) + f(x_n)\right]Parabolic quadrature (requires even nn)

41. Common Mathematical Constants

No.ConstantSymbolApproximate ValueSignificance
494Piπ\pi≈3.141592653589793\approx 3.141592653589793Ratio of circumference to diameter of circle
495Euler’s Numberee≈2.718281828459045\approx 2.718281828459045Base of natural logarithm
496Pythagoras’ Constant2\sqrt{2}≈1.414213562373095\approx 1.414213562373095Diagonal of unit square / irrational root
497Theodorus’ Constant3\sqrt{3}≈1.732050807568877\approx 1.732050807568877Diagonal of unit cube
498Golden Ratioφ=1+52\varphi = \frac{1 + \sqrt{5}}{2}≈1.618033988749895\approx 1.618033988749895Positive root of x2−x−1=0x^2 - x - 1 = 0
499Euler-Mascheroni Constantγ\gamma≈0.577215664901532\approx 0.577215664901532Limiting difference between harmonic series and natural log
500Imaginary Unitii−1\sqrt{-1}Fundamental unit of complex numbers (i2=−1i^2 = -1)

42. Useful Unit Conversions

No.DimensionConversion IdentityScale Factor
501Length1 km=1000 m1\text{ km} = 1000\text{ m}Metric length
502Length1 m=100 cm=1000 mm1\text{ m} = 100\text{ cm} = 1000\text{ mm}Metric length
503Length1 in=2.54 cm1\text{ in} = 2.54\text{ cm}Imperial to metric exact definition
504Length1 ft=12 in=0.3048 m1\text{ ft} = 12\text{ in} = 0.3048\text{ m}Imperial foot
505Length1 yd=3 ft=0.9144 m1\text{ yd} = 3\text{ ft} = 0.9144\text{ m}Imperial yard
506Length1 mi=5280 ft≈1.60934 km1\text{ mi} = 5280\text{ ft} \approx 1.60934\text{ km}Statute mile
507Area1 m2=104 cm2=106 mm21\text{ m}^2 = 10^4\text{ cm}^2 = 10^6\text{ mm}^2Metric area
508Area1 km2=106 m2=100 ha1\text{ km}^2 = 10^6\text{ m}^2 = 100\text{ ha}1 hectare = 104 m210^4\text{ m}^2
509Volume1 m3=106 cm3=1000 L1\text{ m}^3 = 10^6\text{ cm}^3 = 1000\text{ L}1 cubic meter
510Volume1 L=1000 mL=1000 cm31\text{ L} = 1000\text{ mL} = 1000\text{ cm}^3Metric liquid volume
511Angle180∘=π rad180^\circ = \pi\text{ rad}Straight angle equivalence
512Angle1 rad=180∘π≈57.2958∘1\text{ rad} = \frac{180^\circ}{\pi} \approx 57.2958^\circRadian to degree conversion

43. Quick Reference Tables

Common Derivatives Reference

No.Function f(x)f(x)Derivative f′(x)f'(x)Domain / Notes
513cc00Constant function
514xnx^nnxn−1n x^{n-1}Power rule (n∈Rn \in \mathbb{R})
515exe^xexe^xNatural exponential
516axa^xaxln⁡aa^x \ln aa>0,a≠1a > 0, a \ne 1
517ln⁡x\ln x1x\frac{1}{x}x>0x > 0
518sin⁡x\sin xcos⁡x\cos xx∈Rx \in \mathbb{R}
519cos⁡x\cos x−sin⁡x-\sin xx∈Rx \in \mathbb{R}
520tan⁡x\tan xsec⁡2x\sec^2 xx≠π2+kπx \ne \frac{\pi}{2} + k\pi
521cot⁡x\cot x−csc⁡2x-\csc^2 xx≠kπx \ne k\pi
522sec⁡x\sec xsec⁡xtan⁡x\sec x\tan xx≠π2+kπx \ne \frac{\pi}{2} + k\pi
523csc⁡x\csc x−csc⁡xcot⁡x-\csc x\cot xx≠kπx \ne k\pi
524arcsin⁡x\arcsin x11−x2\frac{1}{\sqrt{1 - x^2}}∣x∣<1\vert x\vert < 1
525arccos⁡x\arccos x−11−x2-\frac{1}{\sqrt{1 - x^2}}∣x∣<1\vert x\vert < 1
526arctan⁡x\arctan x11+x2\frac{1}{1 + x^2}x∈Rx \in \mathbb{R}
527sinh⁡x\sinh xcosh⁡x\cosh xx∈Rx \in \mathbb{R}
528cosh⁡x\cosh xsinh⁡x\sinh xx∈Rx \in \mathbb{R}
529tanh⁡x\tanh xsech⁡2x\operatorname{sech}^2 xx∈Rx \in \mathbb{R}

Common Integrals Reference

No.Function f(x)f(x)Indefinite Integral ∫f(x) dx\int f(x)\,dxDomain / Notes
530cccx+Ccx + CConstant
531xnx^nxn+1n+1+C\frac{x^{n+1}}{n+1} + Cn≠−1n \ne -1
5321x\frac{1}{x}ln⁡∣x∣+C\ln\vert x\vert + Cx≠0x \ne 0
533exe^xex+Ce^x + CNatural exponential
534axa^xaxln⁡a+C\frac{a^x}{\ln a} + Ca>0,a≠1a > 0, a \ne 1
535sin⁡x\sin x−cos⁡x+C-\cos x + CTrig antiderivative
536cos⁡x\cos xsin⁡x+C\sin x + CTrig antiderivative
537sec⁡2x\sec^2 xtan⁡x+C\tan x + Cx≠π2+kπx \ne \frac{\pi}{2} + k\pi
538csc⁡2x\csc^2 x−cot⁡x+C-\cot x + Cx≠kπx \ne k\pi
539sec⁡xtan⁡x\sec x\tan xsec⁡x+C\sec x + Cx≠π2+kπx \ne \frac{\pi}{2} + k\pi
540csc⁡xcot⁡x\csc x\cot x−csc⁡x+C-\csc x + Cx≠kπx \ne k\pi
54111+x2\frac{1}{1 + x^2}arctan⁡x+C\arctan x + Cx∈Rx \in \mathbb{R}
54211−x2\frac{1}{\sqrt{1 - x^2}}arcsin⁡x+C\arcsin x + C∣x∣<1\vert x\vert < 1

Common Trigonometric Values

θ\theta0∘0^\circ (00)30∘30^\circ (π/6\pi/6)45∘45^\circ (π/4\pi/4)60∘60^\circ (π/3\pi/3)90∘90^\circ (π/2\pi/2)
sin⁡θ\sin\theta0012\frac{1}{2}22\frac{\sqrt{2}}{2}32\frac{\sqrt{3}}{2}11
cos⁡θ\cos\theta1132\frac{\sqrt{3}}{2}22\frac{\sqrt{2}}{2}12\frac{1}{2}00
tan⁡θ\tan\theta0013\frac{1}{\sqrt{3}}113\sqrt{3}undefined

Reference & Appendices

Formula Selection Guide

Problem TypeTarget Section / FormulasKey Method / Identity
Expand or factor algebraic expressionsAlgebraic Identities (Sec. 4)Binomial, difference of squares, cubes
Find roots of polynomial equationsEquations and Inequalities (Sec. 5 & 6)Quadratic formula, Vieta’s relations, factoring
Solve exponential / logarithmic equationsLogarithms (Sec. 7)Change of base, product and power rules
Summing series with constant differenceSequences and Series (Sec. 8)Arithmetic Progression (SnS_n)
Summing geometric series / decay processesSequences and Series (Sec. 8)Geometric Progression (Sn,S∞S_n, S_\infty)
Combinations & permutations of objectsCounting & Combinatorics (Sec. 10)nPr,{}^n P_r, {}^n C_r, stars and bars
Finding angles, lengths, or sides in trianglesTrigonometry & Triangles (Sec. 18 & 21)SOHCAHTOA, Law of Sines, Law of Cosines
Distance, slope, or line equations in 2DCoordinate Geometry & Lines (Sec. 13 & 14)Distance formula, slope-intercept, point-to-line
Circles, arcs, and sector areasCircles (Sec. 15)Standard circle form, arc length s=rθs = r\theta
Conic curves (parabolas, ellipses, hyperbolas)Conic Sections (Sec. 16)Standard forms, focal distance c2c^2, eccentricity ee
3D volumes, surface areas, and slant heights3D Mensuration (Sec. 20)Cylinder, cone, sphere, prism formulas
Rates of change, tangents, optimizationDifferentiation (Sec. 25 & 26)Product/chain rules, critical points f′(x)=0f'(x)=0
Accumulation, curve areas, solid volumesIntegration (Sec. 27 & 28)Fundamental theorem, substitution, disk/shell
Dynamic rate processes, growth, half-lifeDifferential Equations (Sec. 29)Separation of variables, integrating factor
Spatial vectors, angles, planes, projectionsVectors (Sec. 30)Dot product (angles), cross product (normal/area)
Linear systems, transformations, determinantsMatrices & Determinants (Sec. 31 & 32)Matrix multiplication, A−1A^{-1}, det⁡A\det A
Chance events, conditional odds, Bayesian inferenceProbability (Sec. 33)Addition/product rules, Bayes’ theorem
Dataset spread, variance, linear regressionStatistics (Sec. 34)Mean, sample variance s2s^2, correlation rr
Logic propositions, set intersectionsDiscrete Mathematics (Sec. 35)De Morgan’s laws, inclusion-exclusion
Divisibility, modular equations, primesNumber Theory (Sec. 36)Euclidean algorithm, modular inverse, totient
Networks, trees, graph connectivityGraph Theory (Sec. 37)Handshaking lemma, Euler formula V−E+F=2V - E + F = 2
Interest, depreciation, loan paymentsFinancial Mathematics (Sec. 39)Compound interest, amortization payment PMTPMT
Numerical root finding and numerical integrationNumerical Methods (Sec. 40)Newton-Raphson, composite trapezoidal rule

Important Notation

SymbolMathematical MeaningStandard Context
π\piCircle ratio constant (3.14159…3.14159\dots)Geometry, trigonometry, calculus
eeEuler’s natural logarithm base (2.71828…2.71828\dots)Growth models, calculus, complex analysis
iiImaginary unit (i2=−1i^2 = -1)Complex numbers, algebra
∑\sumSummation operatorSeries, statistics, discrete math
∏\prodProduct operatorFactorials, number theory, linear algebra
∫\intIntegral operatorCalculus, continuous distributions
∂\partialPartial derivativeMultivariable calculus, PDEs
∇\nablaDel / gradient vector differential operatorVector calculus
Δ\DeltaDifference / change; discriminantAlgebra, calculus
∞\inftyInfinityLimits, unbounded domains
∀\forallUniversal quantifier (“for all”)Logic, proofs, set theory
∃\existsExistential quantifier (“there exists”)Logic, proofs
∈\inElement ofSet membership
⊆\subseteqSubset ofSet theory
≈\approxApproximately equal toNumerical methods, approximations
≡\equivIdentically equal / congruent modulo mmAlgebra, number theory, logic
∝\proptoProportional toRatios, variation
⊥\perpPerpendicular toGeometry, orthogonal vectors
∥\parallelParallel toGeometry, lines

Final Notes

  • Angle Units: Trigonometric calculus formulas (derivatives and integrals) strictly assume angles are measured in radians.
  • Logarithmic Notation: log⁡x\log x without an explicit base may refer to base 1010 in applied contexts or the natural logarithm ln⁡x\ln x (base ee) in advanced mathematics; ln⁡x\ln x unambiguously denotes base ee.
  • Principal Values: For square roots over real numbers, x\sqrt{x} denotes the non-negative principal root.
  • Domain Restrictions: Always verify domain validity (e.g. non-zero denominators, strictly positive logarithmic arguments, non-negative radical radicands) before applying identities.

Explore practical applications of these mathematical principles in software engineering:


Last updated: 2026-09-30


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