MATHEMATICS

JEE Mathematics Formula Sheet

A curated, chapter-wise reference of Mathematics formulas, optimized for JEE Mains & Advanced preparation. Download printable PDF sheets for offline study.

Exam suite:

1. Sets & Relations

Sets, representations and algebra of sets

De Morgan's Laws of Sets

M A
(AB)=AB(A \cup B)' = A' \cap B'
(AB)=AB(A \cap B)' = A' \cup B'
Parameters & Definitions

AA' and BB' represent the complements of sets AA and BB, while \cup and \cap represent union and intersection.

Fundamental set identities relating union, intersection, and complements.

Union, intersection and Cartesian product of sets

Cardinality of Union of Sets

M A
n(AB)=n(A)+n(B)n(AB)n(A \cup B) = n(A) + n(B) - n(A \cap B)
n(ABC)=n(A)+n(B)+n(C)n(AB)n(BC)n(CA)+n(ABC)n(A \cup B \cup C) = n(A) + n(B) + n(C) - n(A \cap B) - n(B \cap C) - n(C \cap A) + n(A \cap B \cap C)
Parameters & Definitions

n(S)n(S) represents the number of elements in set SS; \cup and \cap represent union and intersection respectively.

Formula to count elements in the union of two or three finite sets.

Relations: domain, co-domain and range

Relation Domain and Range Definitions

M A
Domain(R)={aA:(a,b)R}\text{Domain}(R) = \{a \in A : (a,b) \in R\}
Range(R)={bB:(a,b)R}\text{Range}(R) = \{b \in B : (a,b) \in R\}
Parameters & Definitions

RR is relation, AA is domain set, BB is co-domain set, and (a,b)(a,b) represents ordered pairs in RR.

Formally defines the domain and range sets of a binary relation RA×BR \subseteq A \times B.

Types of relations and equivalence relations

Number of Relations on a Set

M A
Total Relations from A to B=2n(A)×n(B)\text{Total Relations from A to B} = 2^{n(A) \times n(B)}
Reflexive Relations on A=2n2nwhere n=n(A)\text{Reflexive Relations on A} = 2^{n^2 - n} \quad \text{where } n = n(A)
Symmetric Relations on A=2n(n+1)2where n=n(A)\text{Symmetric Relations on A} = 2^{\frac{n(n+1)}{2}} \quad \text{where } n = n(A)
Parameters & Definitions

n(S)n(S) represents the number of elements in set SS, and nn is the cardinality of set AA.

Formulas to calculate total, reflexive, and symmetric relations on a finite set.

2. Functions

Real-valued functions, domain and range

Fundamental Domain Conditions

M A
1g(x)    g(x)0\frac{1}{g(x)} \implies g(x) \neq 0
g(x)    g(x)0\sqrt{g(x)} \implies g(x) \ge 0
logb(g(x))    g(x)>0\log_b(g(x)) \implies g(x) > 0
Parameters & Definitions

g(x)g(x) is a real-valued sub-function, and     \implies represents constraints for mathematical definedness.

Mathematical domain conditions for real-valued rational, radical, and logarithmic functions.

Types of functions and graphical representations

Symmetry and Periodicity of Functions

M A
f(x)=f(x)(Even Function)f(-x) = f(x) \quad \text{(Even Function)}
f(x)=f(x)(Odd Function)f(-x) = -f(x) \quad \text{(Odd Function)}
f(x+T)=f(x)(Periodic with period T)f(x + T) = f(x) \quad \text{(Periodic with period } T\text{)}
Parameters & Definitions

f(x)f(x) is a real-valued function, and T>0T > 0 is the smallest positive constant satisfying the relation.

Mathematical definitions of even/odd functions and periodic functions.

Injectivity, surjectivity and bijectivity

Injective (One-to-One) Functions Count

M A
Ninjective={P(b,a)if ba0if b<aN_{\text{injective}} = \begin{cases} P(b, a) & \text{if } b \ge a \\ 0 & \text{if } b < a \end{cases}
Parameters & Definitions

a=n(A)a = n(A) is the size of the domain, b=n(B)b = n(B) is the size of the co-domain, and P(b,a)P(b,a) represents permutations.

Formula to calculate the number of injective functions from set AA to set BB.

Composition and inverse of functions

Composition and Inverse of Functions

M A
(gf)(x)=g(f(x))(g \circ f)(x) = g(f(x))
f(x)=y    f1(y)=x(if f is one-to-one and onto)f(x) = y \iff f^{-1}(y) = x \quad \text{(if } f \text{ is one-to-one and onto)}
Parameters & Definitions

gfg \circ f is the composite function of ff and gg, and f1f^{-1} is the inverse function of ff.

Mathematical definitions of function composition and the condition for the existence of an inverse.

3. Complex Numbers

Algebraic properties of complex numbers

Properties of Conjugate and Modulus

M A
z1±z2=z1±z2z1z2=z1z2\overline{z_1 \pm z_2} = \overline{z_1} \pm \overline{z_2} \quad \overline{z_1 \cdot z_2} = \overline{z_1} \cdot \overline{z_2}
z1z2=z1z2z1z2=z1z2(z20)|z_1 \cdot z_2| = |z_1| \cdot |z_2| \quad \left| \frac{z_1}{z_2} \right| = \frac{|z_1|}{|z_2|} \quad (z_2 \ne 0)
Parameters & Definitions

z1,z2z_1, z_2 are complex numbers, z\overline{z} represents the complex conjugate of zz, and z|z| represents the modulus.

Key algebraic relationships for the conjugate and modulus of complex numbers.

Modulus, argument, trigonometric and Euler forms

Trigonometric and Euler Representations

M A
z=r(cosθ+isinθ)=reiθz = r (\cos\theta + i\sin\theta) = r e^{i\theta}
r=z=x2+y2θ=arg(z)=tan1(yx)r = |z| = \sqrt{x^2 + y^2} \quad \theta = \text{arg}(z) = \tan^{-1}\left(\frac{y}{x}\right)
Parameters & Definitions

rr is the modulus, θ\theta is the argument (amplitude), and i=1i = \sqrt{-1} is the imaginary unit.

Polar representation of a complex number z=x+iyz = x + iy.

Square root of a complex number

Square Root of a Complex Number

A
a+ib=±(z+a2+isgn(b)za2)\sqrt{a + ib} = \pm \left( \sqrt{\frac{|z| + a}{2}} + i \operatorname{sgn}(b) \sqrt{\frac{|z| - a}{2}} \right)
Parameters & Definitions

z=a2+b2|z| = \sqrt{a^2 + b^2}, and sgn(b)\operatorname{sgn}(b) is 11 if b0b \ge 0 and 1-1 if b<0b < 0.

Algebraic formula to find the square root of z=a+ibz = a + ib.

Triangle inequality of complex numbers

Triangle Inequalities for Complex Numbers

A
z1z2z1±z2z1+z2||z_1| - |z_2|| \le |z_1 \pm z_2| \le |z_1| + |z_2|
Parameters & Definitions

z1z_1 and z2z_2 are complex numbers, and z|z| represents the modulus of zz.

Bound limits for the modulus of the sum and difference of two complex numbers.

4. Quadratic Equations

Quadratic solutions, nature of roots and Vieta's relations

Roots Formula and Vieta's Relations

M A
x=b±D2awhere D=b24acx = \frac{-b \pm \sqrt{D}}{2a} \quad \text{where } D = b^2 - 4ac
α+β=baαβ=ca\alpha + \beta = -\frac{b}{a} \quad \alpha \beta = \frac{c}{a}
Parameters & Definitions

a,b,ca, b, c are coefficients, DD is the discriminant, and α,β\alpha, \beta are the roots.

Formula to solve ax2+bx+c=0ax^2 + bx + c = 0 and the sum/product relationships of its roots α,β\alpha, \beta.

Formation of quadratic equations

Formation of Quadratic Equation from Roots

M A
x2Sx+P=0where S=α+β, P=αβx^2 - S x + P = 0 \quad \text{where } S = \alpha + \beta, \ P = \alpha \beta
Parameters & Definitions

xx is the variable, SS is the sum of the roots, PP is the product of the roots, and α,β\alpha, \beta are the roots.

Standard equation constructed using the sum and product of its roots α,β\alpha, \beta.

Condition for common roots

Condition for One Common Root

M A
(a1c2a2c1)2=(a1b2a2b1)(b1c2b2c1)(a_1 c_2 - a_2 c_1)^2 = (a_1 b_2 - a_2 b_1)(b_1 c_2 - b_2 c_1)
Parameters & Definitions

a1,b1,c1a_1, b_1, c_1 and a2,b2,c2a_2, b_2, c_2 are the coefficients of the two quadratic equations respectively.

Algebraic condition for two quadratic equations to share exactly one root.

5. Matrices

Algebra of matrices, symmetric and skew-symmetric matrices

Symmetric, Skew-Symmetric and Orthogonal Matrices

M A
AT=A(Symmetric)A^T = A \quad \text{(Symmetric)}
AT=A(Skew-Symmetric)A^T = -A \quad \text{(Skew-Symmetric)}
AAT=ATA=I(Orthogonal)A A^T = A^T A = I \quad \text{(Orthogonal)}
Parameters & Definitions

ATA^T is the transpose of square matrix AA, II is the identity matrix, and A-A is the negative matrix of AA.

Definitions based on the transpose of a square matrix AA.

Orthogonal matrices, adjoint and inverse of a square matrix

Inverse of a Square Matrix

M A
A1=1Aadj(A)(if A0)A^{-1} = \frac{1}{|A|} \operatorname{adj}(A) \quad \text{(if } |A| \ne 0\text{)}
Parameters & Definitions

A1A^{-1} is the inverse of matrix AA, A|A| is the determinant of AA, and adj(A)\operatorname{adj}(A) is the adjoint matrix of AA.

Relation linking the inverse of a square matrix to its adjoint and determinant.

6. Determinants

Evaluation of determinants

Evaluation of 2x2 and 3x3 Determinants

M A
det(A)2×2=adbc\det(A)_{2\times 2} = ad - bc
det(A)3×3=a1(b2c3b3c2)b1(a2c3a3c2)+c1(a2b3a3b2)\det(A)_{3\times 3} = a_1(b_2 c_3 - b_3 c_2) - b_1(a_2 c_3 - a_3 c_2) + c_1(a_2 b_3 - a_3 b_2)
Parameters & Definitions

a,b,c,da,b,c,d are elements of a 2×22\times 2 matrix; ai,bi,cia_i, b_i, c_i are elements of a 3×33\times 3 matrix expanding along the first row.

Formulas to compute the determinant value for second and third-order square matrices.

Properties of determinants

Fundamental Properties of Determinants

A
AT=A|A^T| = |A|
kA=knA(for n×n matrix A)|k A| = k^n |A| \quad \text{(for } n \times n \text{ matrix } A\text{)}
AB=AB|A B| = |A| \cdot |B|
Parameters & Definitions

ATA^T is the transpose, kk is a scalar constant, nn is the dimension of the square matrices, and A|A| is the determinant of AA.

Standard properties relating matrix transpose, scalar multiplication, and matrix products to determinants.

Consistency test and Cramer's rule for linear equations

Cramer's Rule for Linear Systems

M A
x=ΔxΔ,y=ΔyΔ,z=ΔzΔ(if Δ0)x = \frac{\Delta_x}{\Delta}, \quad y = \frac{\Delta_y}{\Delta}, \quad z = \frac{\Delta_z}{\Delta} \quad \text{(if } \Delta \ne 0\text{)}
Parameters & Definitions

Δ\Delta is the coefficient determinant, and Δx,Δy,Δz\Delta_x, \Delta_y, \Delta_z are determinants obtained by replacing columns with the constant terms.

Method to solve a system of three simultaneous linear equations using determinants.

7. Permutations & Combinations

Fundamental principle of counting

Multiplication and Addition Principles

M A
Total Ways (AND)=m×n\text{Total Ways (AND)} = m \times n
Total Ways (OR)=m+n\text{Total Ways (OR)} = m + n
Parameters & Definitions

mm is the number of ways task 1 can occur, and nn is the number of ways task 2 can occur.

Core combinatorial rules for compound tasks occurring sequentially (AND) or mutually exclusively (OR).

Permutation and combination formulas

Permutations and Combinations Formulas

M A
P(n,r)=n!(nr)!P(n, r) = \frac{n!}{(n-r)!}
C(n,r)=n!r!(nr)!C(n, r) = \frac{n!}{r!(n-r)!}
Parameters & Definitions

nn is the total number of items, and rr is the number of items to arrange or select.

Formulas to calculate arrangements of rr objects out of nn (P(n,r)P(n,r)) and selections of rr objects out of nn (C(n,r)C(n,r)).

Simple applications of permutations and combinations

Geometric Combinatorics Formulas

M A
Diagonals of a Polygon=n(n3)2\text{Diagonals of a Polygon} = \frac{n(n-3)}{2}
Lines through n points=C(n,2)C(p,2)+1(if p points are collinear)\text{Lines through } n \text{ points} = C(n, 2) - C(p, 2) + 1 \quad \text{(if } p \text{ points are collinear)}
Parameters & Definitions

nn is the number of vertices/points, and pp is the number of collinear points among them.

Formulas to find the number of diagonals, lines, and triangles formed by nn coplanar points.

8. Binomial Theorem

Binomial theorem, general and middle terms

Binomial Theorem and General Term

M A
(x+y)n=r=0nC(n,r)xnryr(x+y)^n = \sum_{r=0}^n C(n, r) x^{n-r} y^r
Tr+1=C(n,r)xnryrT_{r+1} = C(n, r) x^{n-r} y^r
Parameters & Definitions

nn is a positive integer, Tr+1T_{r+1} represents the (r+1)(r+1)-th term in the expansion, and C(n,r)C(n,r) is the binomial coefficient.

Mathematical expansion of (x+y)n(x+y)^n and its (r+1)(r+1)-th term.

Properties of binomial coefficients

Binomial Coefficient Sum Identities

A
C0+C1+C2++Cn=2nC_0 + C_1 + C_2 + \dots + C_n = 2^n
C0C1+C2+(1)nCn=0C_0 - C_1 + C_2 - \dots + (-1)^n C_n = 0
C0+C2+C4+=C1+C3+C5+=2n1C_0 + C_2 + C_4 + \dots = C_1 + C_3 + C_5 + \dots = 2^{n-1}
Parameters & Definitions

CrC_r represents the binomial coefficient C(n,r)C(n,r) for a positive integral index nn.

Formulas for sums of binomial coefficients derived from (1+x)n(1+x)^n expansions.

Multinomial theorem

Multinomial Theorem Expansion

M A
Tgeneral=n!r1!r2!rk!x1r1x2r2xkrk(r1+r2++rk=n)T_{\text{general}} = \frac{n!}{r_1! r_2! \dots r_k!} x_1^{r_1} x_2^{r_2} \dots x_k^{r_k} \quad (r_1 + r_2 + \dots + r_k = n)
Number of Terms=C(n+k1,k1)\text{Number of Terms} = C(n+k-1, k-1)
Parameters & Definitions

nn is the positive power index, kk is the number of variables inside the brackets, and rir_i are non-negative integer powers.

General term and total terms in the expansion of a multinomial expression.

9. Sequences & Series

Arithmetic Progression (AP) and Geometric Progression (GP)

Sums of Arithmetic and Geometric Progressions

M A
Sn,AP=n2[2a+(n1)d]S_{n, AP} = \frac{n}{2} [2a + (n-1)d]
Sn,GP=a(rn1r1)(r1)S_{n, GP} = a \left( \frac{r^n - 1}{r - 1} \right) \quad (r \ne 1)
S,GP=a1r(r<1)S_{\infty, GP} = \frac{a}{1-r} \quad (|r| < 1)
Parameters & Definitions

aa is the first term, dd is the common difference, rr is the common ratio, and SnS_n represents the sum of nn terms.

Formulas for sum of nn terms in AP and GP, and the sum of an infinite GP (r<1|r| < 1).

Arithmetic, Geometric and Harmonic means relation

Arithmetic, Geometric, and Harmonic Means Relation

M A
A.M.G.M.H.M.    a+b2ab2aba+bA.M. \ge G.M. \ge H.M. \implies \frac{a+b}{2} \ge \sqrt{ab} \ge \frac{2ab}{a+b}
Parameters & Definitions

a,ba, b are positive real numbers.

Inequality relation for positive real numbers.

Harmonic Progression (HP) and AGP

Harmonic and Arithmetico-Geometric Progressions

A
tn,HP=1a+(n1)dt_{n, HP} = \frac{1}{a + (n-1)d}
S,AGP=a1r+dr(1r)2for r<1S_{\infty, AGP} = \frac{a}{1-r} + \frac{dr}{(1-r)^2} \quad \text{for } |r| < 1
Parameters & Definitions

aa is first term of AP/AGP, dd is common difference, rr is common ratio of GP part, and SS_{\infty} is sum to infinity.

General term of HP and the sum to infinity of an AGP series.

10. Limits, Continuity & Differentiability

Algebra of limits and standard limits

Standard Limit Evaluations

M A
limx0sinxx=1\lim_{x \to 0} \frac{\sin x}{x} = 1
limx0ex1x=1\lim_{x \to 0} \frac{e^x - 1}{x} = 1
limx0(1+x)1/x=e\lim_{x \to 0} (1+x)^{1/x} = e
Parameters & Definitions

xx is a real variable approaching 00, and ee is Euler's number.

Fundamental trigonometric and exponential limit identities.

Continuity of real-valued functions

Mathematical Criterion for Continuity

M A
limxcf(x)=limxc+f(x)=f(c)\lim_{x \to c^-} f(x) = \lim_{x \to c^+} f(x) = f(c)
Parameters & Definitions

f(x)f(x) is the function, cc is the point of interest, and the left-hand and right-hand limits must match the value f(c)f(c).

Condition for a function f(x)f(x) to be continuous at a specific point x=cx = c.

Differentiability, derivative basics and chain rule

Derivative from First Principles

M A
f(x)=limh0f(x+h)f(x)hf'(x) = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}
Parameters & Definitions

f(x)f'(x) is the derivative, and hh is an infinitesimally small change in the input variable xx.

Limit definition of the derivative of a real-valued function f(x)f(x).

Rolle's and Lagrange's Mean Value Theorems

Rolle's and Lagrange's Mean Value Theorems

A
f(c)=0c(a,b)(Rolle’s Theorem if f(a)=f(b))f'(c) = 0 \quad c \in (a, b) \quad \text{(Rolle's Theorem if } f(a)=f(b)\text{)}
f(c)=f(b)f(a)bac(a,b)(Lagrange’s MVT)f'(c) = \frac{f(b) - f(a)}{b - a} \quad c \in (a, b) \quad \text{(Lagrange's MVT)}
Parameters & Definitions

f(x)f(x) is continuous on [a,b][a,b] and differentiable on (a,b)(a,b), and cc is a point inside the interval.

Core theorems of differential calculus for continuous and differentiable functions on [a,b][a,b].

11. Methods of Differentiation

Product, quotient and chain rules of differentiation

Rules of Differentiation

M A
(uv)=uv+uv(u v)' = u' v + u v'
(uv)=uvuvv2\left( \frac{u}{v} \right)' = \frac{u' v - u v'}{v^2}
dydx=dydududx(Chain Rule)\frac{dy}{dx} = \frac{dy}{du} \cdot \frac{du}{dx} \quad \text{(Chain Rule)}
Parameters & Definitions

u,v,yu, v, y are differentiable functions of a real variable xx, and uu is a function of xx.

Formulas for differentiating products, quotients, and compositions of functions.

Derivatives of trigonometric, exponential and parametric functions

Derivatives of Standard Functions

M A
ddx(sinx)=cosxddx(ex)=ex\frac{d}{dx}(\sin x) = \cos x \quad \frac{d}{dx}(e^x) = e^x
ddx(lnx)=1x(x>0)ddx(tan1x)=11+x2\frac{d}{dx}(\ln x) = \frac{1}{x} \quad (x > 0) \quad \frac{d}{dx}(\tan^{-1} x) = \frac{1}{1+x^2}
Parameters & Definitions

xx is a real variable within the valid domain of each corresponding function.

Standard formulas for differentiation of basic trigonometric, logarithmic and exponential functions.

12. Applications of Derivative

Rate of change of physical quantities

Related Rates of Change

M A
dydt=dydxdxdt\frac{dy}{dt} = \frac{dy}{dx} \cdot \frac{dx}{dt}
Parameters & Definitions

yy is a function of xx, and both are differentiable functions of time tt.

Formula linking the rate of change of dependent variables using chain rule.

Monotonic functions (increasing and decreasing)

Monotonicity and Tangent Slope

M A
f(x)>0    Increasing Functionf'(x) > 0 \implies \text{Increasing Function}
f(x)<0    Decreasing Functionf'(x) < 0 \implies \text{Decreasing Function}
mtangent=f(x0)m_{tangent} = f'(x_0)
Parameters & Definitions

f(x)f(x) is a differentiable function, and mtangentm_{tangent} is the slope of the tangent at x0x_0.

Conditions using the first derivative to determine increasing/decreasing nature, and the slope of a tangent.

Maxima and minima of functions

First and Second Derivative Tests

M A
f(c)=0 and f(c)<0    c is local maximumf'(c) = 0 \text{ and } f''(c) < 0 \implies c \text{ is local maximum}
f(c)=0 and f(c)>0    c is local minimumf'(c) = 0 \text{ and } f''(c) > 0 \implies c \text{ is local minimum}
Parameters & Definitions

f(x)f(x) is a twice-differentiable function, and cc is a critical point inside its domain.

Calculus tests to locate and classify local extrema of a function.

Equations of tangents and normals

Equations of Tangent and Normal to a Curve

A
yy1=f(x1)(xx1)y - y_1 = f'(x_1) (x - x_1)
yy1=1f(x1)(xx1)y - y_1 = -\frac{1}{f'(x_1)} (x - x_1)
Parameters & Definitions

(x1,y1)(x_1, y_1) is the point on the curve, and f(x1)f'(x_1) is the slope of the tangent.

Formulas to find the lines tangent and normal to y=f(x)y = f(x) at (x1,y1)(x_1, y_1).

13. Indefinite Integration

Indefinite integrals and integration by substitution

Standard Indefinite Integrals

M A
xndx=xn+1n+1+C(n1)\int x^n \, dx = \frac{x^{n+1}}{n+1} + C \quad (n \ne -1)
1xdx=lnx+C\int \frac{1}{x} \, dx = \ln|x| + C
Parameters & Definitions

nn is a constant exponent, xx is a real variable, and CC is the integration constant.

Standard integration formulas for power and reciprocal functions.

Integration by parts

Integration by Parts Formula

M A
udv=uvvdu    f(x)g(x)dx=f(x)g(x)dx(f(x)g(x)dx)dx\int u \, dv = u v - \int v \, du \implies \int f(x) g(x) \, dx = f(x) \int g(x) \, dx - \int \left( f'(x) \int g(x) \, dx \right) dx
Parameters & Definitions

u,v,f(x),g(x)u, v, f(x), g(x) are differentiable functions of xx.

Formula derived from product rule to integrate the product of two functions.

Integration using partial fractions

Integration by Partial Fractions

M A
px+q(xa)(xb)=Axa+Bxb(ab)\frac{px + q}{(x-a)(x-b)} = \frac{A}{x-a} + \frac{B}{x-b} \quad (a \ne b)
Parameters & Definitions

p,q,a,bp,q,a,b are constants, and A,BA,B are solved numerical coefficients.

Decomposition template of a rational function into simpler fractions for integration.

14. Definite Integration

Evaluation and Fundamental Theorem of Calculus

Fundamental Theorem of Calculus and Leibniz Rule

M A
abf(x)dx=F(b)F(a)where F(x)=f(x)\int_a^b f(x) \, dx = F(b) - F(a) \quad \text{where } F'(x) = f(x)
ddxψ(x)ϕ(x)f(t)dt=f(ϕ(x))ϕ(x)f(ψ(x))ψ(x)\frac{d}{dx} \int_{\psi(x)}^{\phi(x)} f(t) \, dt = f(\phi(x)) \phi'(x) - f(\psi(x)) \psi'(x)
Parameters & Definitions

ff is continuous, FF is antiderivative, and ϕ(x),ψ(x)\phi(x), \psi(x) are differentiable boundary functions.

FTC evaluation formula and Leibniz rule for differentiation under the integral sign.

Properties of definite integrals (including King's property)

Properties of Definite Integrals (King's Property)

M A
abf(x)dx=abf(a+bx)dx\int_a^b f(x) \, dx = \int_a^b f(a+b-x) \, dx
02af(x)dx=0af(x)dx+0af(2ax)dx\int_0^{2a} f(x) \, dx = \int_0^a f(x) \, dx + \int_0^a f(2a-x) \, dx
Parameters & Definitions

f(x)f(x) is an integrable function on the specified intervals, and a,ba, b are real limits.

Fundamental symmetry properties of definite integrals, including the King's Property.

15. Area Under Curves

Areas of regions bounded by simple curves

Area Under a Single Curve

M A
A=abf(x)dx(if f(x)0 on [a,b])A = \int_a^b f(x) \, dx \quad \text{(if } f(x) \ge 0 \text{ on } [a,b]\text{)}
Parameters & Definitions

AA is the area of the region, and x=ax = a to x=bx = b are boundary lines.

Integral formula calculating the area of a region bounded by y=f(x)y = f(x) and the x-axis.

Area bounded between two curves

Area Bounded Between Two Curves

M A
A=abf(x)g(x)dxA = \int_a^b |f(x) - g(x)| \, dx
Parameters & Definitions

AA is the bounded area, and f(x),g(x)f(x), g(x) are curves intersecting or bounded at x=ax=a and x=bx=b.

Integral formula calculating the area bounded between curves y=f(x)y = f(x) and y=g(x)y = g(x) from x=ax=a to x=bx=b.

16. Differential Equations

Formation of ordinary differential equations

Formation of Ordinary Differential Equations

M A
F(x,y,y,y,,y(n))=0F(x, y, y', y'', \dots, y^{(n)}) = 0
Parameters & Definitions

xx is independent variable, yy is dependent variable, and y(n)y^{(n)} is the nn-th derivative of yy.

General algebraic ODE expression representing a family of curves.

Variables separable method and homogeneous equations

Separable and Homogeneous Differential Equations

M A
1g(y)dy=f(x)dx\int \frac{1}{g(y)} \, dy = \int f(x) \, dx
y=vx    dydx=v+xdvdx(for homogeneous form dydx=f(y/x))y = v x \implies \frac{dy}{dx} = v + x \frac{dv}{dx} \quad \text{(for homogeneous form } \frac{dy}{dx} = f(y/x)\text{)}
Parameters & Definitions

vv is a temporary helper variable, x,yx, y are coordinate variables, and f,gf, g are functions.

Formulas for variables-separable integration and substitution for homogeneous differential equations.

First-order linear differential equations

First-Order Linear Differential Equation

M A
dydx+Py=Q    I.F.=ePdx\frac{dy}{dx} + P y = Q \implies \text{I.F.} = e^{\int P \, dx}
yI.F.=(QI.F.)dx+Cy \cdot \text{I.F.} = \int (Q \cdot \text{I.F.}) \, dx + C
Parameters & Definitions

PP and QQ are functions of xx only, I.F. is the integrating factor, and CC is the integration constant.

Standard form and solution using an Integrating Factor (I.F.).

17. Straight Lines

Cartesian coordinate system and forms of straight lines

Standard Forms of Straight Line Equations

M A
y=mx+c(Slope-Intercept Form)y = m x + c \quad \text{(Slope-Intercept Form)}
xa+yb=1(Intercept Form)\frac{x}{a} + \frac{y}{b} = 1 \quad \text{(Intercept Form)}
yy1=y2y1x2x1(xx1)(Two-Point Form)y - y_1 = \frac{y_2 - y_1}{x_2 - x_1} (x - x_1) \quad \text{(Two-Point Form)}
Parameters & Definitions

mm is the slope, cc is the y-intercept, a,ba, b are axes intercepts, and (xi,yi)(x_i, y_i) are points on the line.

Standard Cartesian formulations for straight lines in coordinate geometry.

Distance of a point from a line

Distance of a Point from a Line

M A
d=ax1+by1+ca2+b2d = \frac{|a x_1 + b y_1 + c|}{\sqrt{a^2 + b^2}}
Parameters & Definitions

dd is the perpendicular distance, (x1,y1)(x_1, y_1) is the coordinates of the point, and a,b,ca, b, c are the coefficients of the line.

Perpendicular distance from a point (x1,y1)(x_1, y_1) to the line ax+by+c=0ax + by + c = 0.

Angle Between Lines and Parallel Distance

M A
tanθ=m1m21+m1m2\tan\theta = \left| \frac{m_1 - m_2}{1 + m_1 m_2} \right|
dparallel=c1c2a2+b2d_{\text{parallel}} = \frac{|c_1 - c_2|}{\sqrt{a^2 + b^2}}
Parameters & Definitions

m1,m2m_1, m_2 are slopes of the intersecting lines, dparalleld_{\text{parallel}} is distance between lines ax+by+c1=0ax+by+c_1=0 and ax+by+c2=0ax+by+c_2=0.

Calculates the acute angle between two intersecting lines, and the perpendicular distance between two parallel lines.

Foot of Perpendicular and Mirror Image of a Point

M A
xpx1a=ypy1b=ax1+by1+ca2+b2(Foot P)\frac{x_p-x_1}{a} = \frac{y_p-y_1}{b} = -\frac{a x_1 + b y_1 + c}{a^2 + b^2} \quad \text{(Foot } P\text{)}
xix1a=yiy1b=2ax1+by1+ca2+b2(Image I)\frac{x_i-x_1}{a} = \frac{y_i-y_1}{b} = -2\frac{a x_1 + b y_1 + c}{a^2 + b^2} \quad \text{(Image } I\text{)}
Parameters & Definitions

(x1,y1)(x_1, y_1) is the given point, (xp,yp)(x_p, y_p) is the foot of the perpendicular, and (xi,yi)(x_i, y_i) is the mirror image point.

Formulas to find coordinate positions of foot of perpendicular and mirror image of point (x1,y1)(x_1, y_1) with respect to line ax+by+c=0ax+by+c=0.

Family of lines and equations of angle bisectors

Family of Lines and Angle Bisectors

M A
L1+λL2=0L_1 + \lambda L_2 = 0
a1x+b1y+c1a12+b12=±a2x+b2y+c2a22+b22\frac{a_1 x + b_1 y + c_1}{\sqrt{a_1^2 + b_1^2}} = \pm \frac{a_2 x + b_2 y + c_2}{\sqrt{a_2^2 + b_2^2}}
Parameters & Definitions

L1,L2L_1, L_2 are lines, λ\lambda is a parameter, and ai,bi,cia_i, b_i, c_i are line coefficients.

Equations for family of intersecting lines and the bisectors of angles between two lines.

18. Circles

Standard and general equations of a circle

Standard and General Equations of a Circle

M A
(xh)2+(yk)2=r2(x-h)^2 + (y-k)^2 = r^2
x2+y2+2gx+2fy+c=0    Center=(g,f), r=g2+f2cx^2 + y^2 + 2gx + 2fy + c = 0 \implies \text{Center} = (-g, -f), \ r = \sqrt{g^2 + f^2 - c}
Parameters & Definitions

(h,k)(h,k) is the center, rr is the radius, and g,f,cg, f, c are general equation parameters.

Mathematical equations defining a circle in coordinate space.

Equations of tangent and normal to a circle

Equation of Tangent to a Circle (Slope Form)

A
y=mx±a1+m2y = m x \pm a \sqrt{1 + m^2}
Parameters & Definitions

mm is the slope of the tangent, and aa is the radius of the circle.

Slope form tangent equation for x2+y2=a2x^2 + y^2 = a^2.

Chord of contact and director circle

Chord of Contact and Director Circle

A
xx1+yy1=a2(Chord of Contact from (x1,y1))x x_1 + y y_1 = a^2 \quad \text{(Chord of Contact from } (x_1, y_1)\text{)}
x2+y2=2a2(Director Circle of x2+y2=a2)x^2 + y^2 = 2 a^2 \quad \text{(Director Circle of } x^2 + y^2 = a^2\text{)}
Parameters & Definitions

(x1,y1)(x_1, y_1) is an external point, and aa is the radius of the circle.

Equations of chord of contact and director circle for a standard circle.

19. Conic Sections

Standard equations and properties of Parabola, Ellipse, Hyperbola

Standard Equations of Parabola, Ellipse and Hyperbola

M A
y2=4ax(Parabola)y^2 = 4a x \quad \text{(Parabola)}
x2a2+y2b2=1e=1b2a2(Ellipse, a>b)\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \quad e = \sqrt{1 - \frac{b^2}{a^2}} \quad \text{(Ellipse, } a > b\text{)}
x2a2y2b2=1e=1+b2a2(Hyperbola)\frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 \quad e = \sqrt{1 + \frac{b^2}{a^2}} \quad \text{(Hyperbola)}
Parameters & Definitions

a,ba, b are semi-axes lengths, and ee represents the eccentricity of the ellipse or hyperbola.

Standard mathematical equations for the three main conic sections.

Equations of tangents and normals

Equations of Tangents in Slope Form

A
y=mx+am(Parabola tangent)y = m x + \frac{a}{m} \quad \text{(Parabola tangent)}
y=mx±a2m2+b2(Ellipse tangent)y = m x \pm \sqrt{a^2 m^2 + b^2} \quad \text{(Ellipse tangent)}
y=mx±a2m2b2(Hyperbola tangent)y = m x \pm \sqrt{a^2 m^2 - b^2} \quad \text{(Hyperbola tangent)}
Parameters & Definitions

mm is the slope of the tangent line, and a,ba, b are conic parameters.

Tangent equations in terms of slope mm for standard parabola, ellipse, and hyperbola.

20. 3D Geometry

Direction cosines and direction ratios

Direction Cosines and Ratios

M A
l2+m2+n2=1l^2 + m^2 + n^2 = 1
l=aa2+b2+c2m=ba2+b2+c2n=ca2+b2+c2l = \frac{a}{\sqrt{a^2+b^2+c^2}} \quad m = \frac{b}{\sqrt{a^2+b^2+c^2}} \quad n = \frac{c}{\sqrt{a^2+b^2+c^2}}
Parameters & Definitions

l,m,nl, m, n are direction cosines; a,b,ca, b, c are direction ratios.

Mathematical relations linking direction cosines and direction ratios of a vector in 3D.

Line equations in 3D space

Line Equations in 3D Space

M A
r=a+λb\vec{r} = \vec{a} + \lambda \vec{b}
xx1bx=yy1by=zz1bz\frac{x - x_1}{b_x} = \frac{y - y_1}{b_y} = \frac{z - z_1}{b_z}
Parameters & Definitions

a\vec{a} (or (x1,y1,z1)(x_1, y_1, z_1)) is a point on the line, b\vec{b} (or bx,by,bzb_x, b_y, b_z) is the direction vector, and λ\lambda is a scalar parameter.

Vector and symmetric Cartesian equations of a line in 3D space.

Shortest distance between skew lines

Shortest Distance Between Skew Lines

M A
dshortest=(a2a1)(b1×b2)b1×b2d_{shortest} = \frac{|(\vec{a}_2 - \vec{a}_1) \cdot (\vec{b}_1 \times \vec{b}_2)|}{|\vec{b}_1 \times \vec{b}_2|}
Parameters & Definitions

dshortestd_{shortest} is the shortest distance; the lines are defined by r=a1+λb1\vec{r} = \vec{a}_1 + \lambda \vec{b}_1 and r=a2+μb2\vec{r} = \vec{a}_2 + \mu \vec{b}_2.

Formula for the shortest distance between two non-parallel, non-intersecting lines in 3D space.

Plane equations and angle between planes

Plane Equation and Angle Between Planes

M A
ax+by+cz+d=0a x + b y + c z + d = 0
cosθ=a1a2+b1b2+c1c2a12+b12+c12a22+b22+c22\cos \theta = \frac{a_1 a_2 + b_1 b_2 + c_1 c_2}{\sqrt{a_1^2+b_1^2+c_1^2}\sqrt{a_2^2+b_2^2+c_2^2}}
Parameters & Definitions

a,b,ca,b,c are normal coefficients, and θ\theta is the angle between planes with coefficients ai,bi,cia_i, b_i, c_i.

General Cartesian equation of a plane and angle between two planes in 3D.

Distance of a point from a plane

Distance of a Point from a Plane

A
d=ax1+by1+cz1+da2+b2+c2d = \frac{|a x_1 + b y_1 + c z_1 + d|}{\sqrt{a^2 + b^2 + c^2}}
Parameters & Definitions

dd is the perpendicular distance, and a,b,c,da, b, c, d are coefficients of the plane equation.

Perpendicular distance from a point (x1,y1,z1)(x_1, y_1, z_1) to the plane ax+by+cz+d=0ax + by + cz + d = 0.

Line-plane intersection

Angle Between Line and Plane

A
sinθ=bnbn\sin \theta = \frac{\vec{b} \cdot \vec{n}}{|\vec{b}| |\vec{n}|}
Parameters & Definitions

b\vec{b} is the direction vector of the line, n\vec{n} is the normal vector of the plane, and θ\theta is the angle between them.

Formula to calculate the angle between a line and a plane in 3D space.

21. Vector Algebra

Vectors, vector addition and components

Resultant of Vector Addition

M A
R=a+b=a2+b2+2abcosθR = |\vec{a} + \vec{b}| = \sqrt{a^2 + b^2 + 2ab \cos\theta}
tanα=bsinθa+bcosθ\tan \alpha = \frac{b \sin\theta}{a + b \cos\theta}
Parameters & Definitions

RR is the magnitude of resultant, a,ba, b are magnitudes, θ\theta is the angle between vectors, and α\alpha is the angle of resultant with vector a\vec{a}.

Formulas to calculate the magnitude and direction of the sum of two vectors.

Dot product and cross product of vectors

Dot and Cross Products of Vectors

M A
ab=abcosθ\vec{a} \cdot \vec{b} = a b \cos\theta
a×b=absinθn^\vec{a} \times \vec{b} = a b \sin\theta \, \hat{n}
Parameters & Definitions

a,ba, b are magnitudes of vectors a,b\vec{a}, \vec{b}, θ\theta is the angle between them, and n^\hat{n} is the unit normal vector perpendicular to both.

Mathematical definitions of scalar (dot) and vector (cross) products.

Scalar and vector triple products

Scalar and Vector Triple Products

A
[a b c]=a(b×c)=axayazbxbybzcxcycz[\vec{a} \ \vec{b} \ \vec{c}] = \vec{a} \cdot (\vec{b} \times \vec{c}) = \begin{vmatrix} a_x & a_y & a_z \\ b_x & b_y & b_z \\ c_x & c_y & c_z \end{vmatrix}
a×(b×c)=(ac)b(ab)c\vec{a} \times (\vec{b} \times \vec{c}) = (\vec{a} \cdot \vec{c}) \vec{b} - (\vec{a} \cdot \vec{b}) \vec{c}
Parameters & Definitions

a,b,c\vec{a}, \vec{b}, \vec{c} are vectors, and [a b c][\vec{a} \ \vec{b} \ \vec{c}] represents the scalar triple product.

Triple products of vectors and their algebraic properties.

22. Statistics

Measures of central tendency (Mean, Median, Mode)

Empirical Relation of Central Tendency

M A
Mode=3Median2Mean\text{Mode} = 3 \, \text{Median} - 2 \, \text{Mean}
Parameters & Definitions

Mean, Median, and Mode represent standard measures of central tendency in statistics.

Empirical formula connecting mean, median, and mode for moderately asymmetrical distributions.

Measures of dispersion (Variance and Standard Deviation)

Mean, Variance and Standard Deviation

M A
xˉ=1ni=1nxi\bar{x} = \frac{1}{n} \sum_{i=1}^n x_i
σ2=1ni=1n(xixˉ)2=1ni=1nxi2(xˉ)2\sigma^2 = \frac{1}{n} \sum_{i=1}^n (x_i - \bar{x})^2 = \frac{1}{n} \sum_{i=1}^n x_i^2 - (\bar{x})^2
Parameters & Definitions

xˉ\bar{x} is the arithmetic mean, σ2\sigma^2 is variance, σ\sigma is standard deviation, and nn is total count of observations.

Mathematical calculations for statistical dispersion of data.

23. Probability

Conditional probability and independent events

Probability Addition and Multiplication Rules

M A
P(AB)=P(A)+P(B)P(AB)P(A \cup B) = P(A) + P(B) - P(A \cap B)
P(AB)=P(A)P(B)(if A,B are independent)P(A \cap B) = P(A) \cdot P(B) \quad \text{(if } A, B \text{ are independent)}
Parameters & Definitions

P(S)P(S) represents the probability of event SS, \cup is union, and \cap is intersection.

Formulas for union probability and multiplication rule for independent events.

Bayes' theorem

Conditional Probability and Bayes' Theorem

M A
P(AB)=P(AB)P(B)(P(B)>0)P(A | B) = \frac{P(A \cap B)}{P(B)} \quad (P(B) > 0)
P(AiB)=P(BAi)P(Ai)j=1kP(BAj)P(Aj)P(A_i | B) = \frac{P(B | A_i) P(A_i)}{\sum_{j=1}^k P(B | A_j) P(A_j)}
Parameters & Definitions

P(AB)P(A|B) is the probability of event AA given BB has occurred, and AiA_i represent mutually exclusive partition events.

Formulas for conditional probability and the probability of causes (Bayes' Theorem).

Random variables and probability distributions

Expectation and Variance of Random Variables

M A
μ=E(X)=xipi\mu = E(X) = \sum x_i p_i
σ2=Var(X)=E(X2)[E(X)]2=xi2piμ2\sigma^2 = \operatorname{Var}(X) = E(X^2) - [E(X)]^2 = \sum x_i^2 p_i - \mu^2
Parameters & Definitions

xix_i represent values of random variable XX, pip_i is probability of xix_i, μ\mu is mean, and σ2\sigma^2 is variance.

Formulas to compute mean (expectation) and variance of a discrete probability distribution.

Binomial distribution and Bernoulli trials

Binomial Probability Distribution

A
P(X=r)=C(n,r)prqnrP(X = r) = C(n, r) p^r q^{n-r}
Parameters & Definitions

pp is probability of success, q=1pq = 1-p is probability of failure, nn is total trials, and rr is target successes.

Probability of obtaining exactly rr successes in nn independent Bernoulli trials.

24. Trigonometric Ratios & Identities

Trigonometric functions and identities

Compound and Double Angle Formulas

M A
sin(A±B)=sinAcosB±cosAsinB\sin(A \pm B) = \sin A \cos B \pm \cos A \sin B
cos(A±B)=cosAcosBsinAsinB\cos(A \pm B) = \cos A \cos B \mp \sin A \sin B
sin2θ=2sinθcosθ=2tanθ1+tan2θ\sin 2\theta = 2\sin\theta \cos\theta = \frac{2\tan\theta}{1+\tan^2\theta}
Parameters & Definitions

A,B,θA, B, \theta are angles in radians.

Core trigonometric expansion formulas for compound and double angles.

Trigonometric Sum to Product (C-D) Formulas

M A
sinC+sinD=2sin(C+D2)cos(CD2)\sin C + \sin D = 2\sin\left(\frac{C+D}{2}\right)\cos\left(\frac{C-D}{2}\right)
sinCsinD=2cos(C+D2)sin(CD2)\sin C - \sin D = 2\cos\left(\frac{C+D}{2}\right)\sin\left(\frac{C-D}{2}\right)
cosC+cosD=2cos(C+D2)cos(CD2)\cos C + \cos D = 2\cos\left(\frac{C+D}{2}\right)\cos\left(\frac{C-D}{2}\right)
cosCcosD=2sin(C+D2)sin(DC2)\cos C - \cos D = 2\sin\left(\frac{C+D}{2}\right)\sin\left(\frac{D-C}{2}\right)
Parameters & Definitions

C,DC, D are angles in radians.

Identities converting sums and differences of sine and cosine functions into products.

Trigonometric Product to Sum Formulas

M A
2sinAcosB=sin(A+B)+sin(AB)2\sin A\cos B = \sin(A+B) + \sin(A-B)
2cosAsinB=sin(A+B)sin(AB)2\cos A\sin B = \sin(A+B) - \sin(A-B)
2cosAcosB=cos(A+B)+cos(AB)2\cos A\cos B = \cos(A+B) + \cos(A-B)
2sinAsinB=cos(AB)cos(A+B)2\sin A\sin B = \cos(A-B) - \cos(A+B)
Parameters & Definitions

A,BA, B are angles in radians.

Identities converting products of sine and cosine functions into sums or differences.

Triple Angle Formulas

M A
sin3θ=3sinθ4sin3θ\sin 3\theta = 3\sin\theta - 4\sin^3\theta
cos3θ=4cos3θ3cosθ\cos 3\theta = 4\cos^3\theta - 3\cos\theta
tan3θ=3tanθtan3θ13tan2θ\tan 3\theta = \frac{3\tan\theta - \tan^3\theta}{1 - 3\tan^2\theta}
Parameters & Definitions

θ\theta is the angle in radians.

Multiple angle identities expanding functions of 3θ3\theta.

Trigonometric Products and Series Sums

M A
cosθcos2θcos22θcos2n1θ=sin(2nθ)2nsinθ\cos\theta \cos 2\theta \cos 2^2\theta \dots \cos 2^{n-1}\theta = \frac{\sin(2^n \theta)}{2^n \sin\theta}
r=0n1sin(α+rβ)=sin(nβ2)sin(β2)sin(α+(n1)β2)\sum_{r=0}^{n-1} \sin(\alpha + r\beta) = \frac{\sin\left(\frac{n\beta}{2}\right)}{\sin\left(\frac{\beta}{2}\right)} \sin\left(\alpha + (n-1)\frac{\beta}{2}\right)
r=0n1cos(α+rβ)=sin(nβ2)sin(β2)cos(α+(n1)β2)\sum_{r=0}^{n-1} \cos(\alpha + r\beta) = \frac{\sin\left(\frac{n\beta}{2}\right)}{\sin\left(\frac{\beta}{2}\right)} \cos\left(\alpha + (n-1)\frac{\beta}{2}\right)
Parameters & Definitions

θ,α\theta, \alpha are starting angles, β\beta is the common difference angle of the series, and nn is the number of terms.

Products of cosine series and sums of sine/cosine series in arithmetic progressions.

Trigonometric equations and general solutions

General Solutions of Trigonometric Equations

A
sinθ=sinα    θ=nπ+(1)nαnZ\sin\theta = \sin\alpha \implies \theta = n\pi + (-1)^n \alpha \quad n \in \mathbb{Z}
cosθ=cosα    θ=2nπ±αnZ\cos\theta = \cos\alpha \implies \theta = 2n\pi \pm \alpha \quad n \in \mathbb{Z}
tanθ=tanα    θ=nπ+αnZ\tan\theta = \tan\alpha \implies \theta = n\pi + \alpha \quad n \in \mathbb{Z}
Parameters & Definitions

θ\theta is the unknown angle, α\alpha is the principal value, and nn is any integer.

General values for variables solving standard trigonometric equations.

25. Inverse Trigonometric Functions

Inverse trigonometric functions: domain, range and principal value branch

Principal Value Branches of ITF

M A
sin1x[π2,π2]cos1x[0,π]\sin^{-1} x \in \left[-\frac{\pi}{2}, \frac{\pi}{2}\right] \quad \cos^{-1} x \in [0, \pi]
tan1x(π2,π2)\tan^{-1} x \in \left(-\frac{\pi}{2}, \frac{\pi}{2}\right)
Parameters & Definitions

xx is the input variable belonging to the appropriate domain of each inverse function.

Standard ranges (principal value branches) of inverse trigonometric functions.

Properties of inverse trigonometric functions

Inverse Trigonometric Sum Identities

M A
sin1x+cos1x=π2x[1,1]\sin^{-1} x + \cos^{-1} x = \frac{\pi}{2} \quad x \in [-1, 1]
tan1x+cot1x=π2xR\tan^{-1} x + \cot^{-1} x = \frac{\pi}{2} \quad x \in \mathbb{R}
Parameters & Definitions

xx represents the input variable within its valid domain.

Standard value identities of inverse trigonometric relations.

Inverse Trig Sum, Difference and Double Angle Conversions

M A
tan1x±tan1y=tan1(x±y1xy)(for xy<1 or xy>1)\tan^{-1} x \pm \tan^{-1} y = \tan^{-1}\left(\frac{x \pm y}{1 \mp xy}\right) \quad \text{(for } xy < 1 \text{ or } xy > -1\text{)}
2tan1x=sin1(2x1+x2)=cos1(1x21+x2)=tan1(2x1x2)2\tan^{-1} x = \sin^{-1}\left(\frac{2x}{1+x^2}\right) = \cos^{-1}\left(\frac{1-x^2}{1+x^2}\right) = \tan^{-1}\left(\frac{2x}{1-x^2}\right)
Parameters & Definitions

x,yx, y are input variables within their appropriate domains.

Formulas for sum and difference of inverse tangents and conversions of 2tan1x2\tan^{-1} x.

26. Properties of Triangles

Sine rule, Cosine rule and Projection rule

Sine Rule and Cosine Rule of Triangles

A
asinA=bsinB=csinC=2R\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} = 2R
cosA=b2+c2a22bc\cos A = \frac{b^2 + c^2 - a^2}{2bc}
Parameters & Definitions

a,b,ca, b, c are lengths of sides opposite to angles A,B,CA, B, C respectively, and RR is the circumradius of the triangle.

Relationships between the sides and angles of a triangle.

Projection Rule and Napier's Analogy

M A
a=bcosC+ccosBb=ccosA+acosCc=acosB+bcosAa = b\cos C + c\cos B \quad b = c\cos A + a\cos C \quad c = a\cos B + b\cos A
tan(BC2)=bcb+ccot(A2)\tan\left(\frac{B-C}{2}\right) = \frac{b-c}{b+c}\cot\left(\frac{A}{2}\right)
Parameters & Definitions

a,b,ca, b, c are side lengths opposite to angles A,B,CA, B, C respectively.

Projection of side lengths in triangles and tangent-based angle/side relationships.

Half-angle formulas, circumradius and inradius

Circumradius and Inradius of Triangles

A
R=abc4ΔR = \frac{a b c}{4 \Delta}
r=Δs=(sa)tan(A2)r = \frac{\Delta}{s} = (s - a) \tan\left(\frac{A}{2}\right)
Parameters & Definitions

a,b,ca,b,c are side lengths, Δ\Delta is area of the triangle, ss is the semi-perimeter, and AA is the opposite angle.

Formulas connecting circumradius (RR) and inradius (rr) to the sides and area of a triangle.

Half-Angle and Area Formulas

M A
sin(A2)=(sb)(sc)bccos(A2)=s(sa)bc\sin\left(\frac{A}{2}\right) = \sqrt{\frac{(s-b)(s-c)}{bc}} \quad \cos\left(\frac{A}{2}\right) = \sqrt{\frac{s(s-a)}{bc}}
tan(A2)=(sb)(sc)s(sa)=Δs(sa)\tan\left(\frac{A}{2}\right) = \sqrt{\frac{(s-b)(s-c)}{s(s-a)}} = \frac{\Delta}{s(s-a)}
Δ=s(sa)(sb)(sc)=rs=abc4R\Delta = \sqrt{s(s-a)(s-b)(s-c)} = rs = \frac{abc}{4R}
Parameters & Definitions

a,b,ca, b, c are side lengths, s=a+b+c2s = \frac{a+b+c}{2} is the semi-perimeter, Δ\Delta is the area of the triangle, rr is the inradius, and RR is the circumradius.

Sine, cosine, and tangent half-angle formulas in terms of semi-perimeter (ss), and Heron's area formula.

Ex-Radii of Triangles

M A
r1=Δsa=stan(A2)=4Rsin(A2)cos(B2)cos(C2)r_1 = \frac{\Delta}{s-a} = s\tan\left(\frac{A}{2}\right) = 4R\sin\left(\frac{A}{2}\right)\cos\left(\frac{B}{2}\right)\cos\left(\frac{C}{2}\right)
r2=Δsb=stan(B2)=4Rcos(A2)sin(B2)cos(C2)r_2 = \frac{\Delta}{s-b} = s\tan\left(\frac{B}{2}\right) = 4R\cos\left(\frac{A}{2}\right)\sin\left(\frac{B}{2}\right)\cos\left(\frac{C}{2}\right)
r3=Δsc=stan(C2)=4Rcos(A2)cos(B2)sin(C2)r_3 = \frac{\Delta}{s-c} = s\tan\left(\frac{C}{2}\right) = 4R\cos\left(\frac{A}{2}\right)\cos\left(\frac{B}{2}\right)\sin\left(\frac{C}{2}\right)
Parameters & Definitions

r1,r2,r3r_1, r_2, r_3 are ex-radii opposite to vertices A,B,CA, B, C respectively, ss is the semi-perimeter, Δ\Delta is the area, and RR is the circumradius.

Formulas for circumradius and inradius values of escribed (outer) circles tangent to side extensions.