Formula Cheat Sheet for CBSE Class 11 Mathematics

Official 100% syllabus-accurate formula sheet for exam revision.

Standard Form

z = x + iy, where i = \sqrt(-1)

Modulus of z (|z|)

|z| = \sqrt(x² + y²)

Powers of i

i² = -1, i³ = -i, i&sup4; = 1

Euler's Form

e^{iθ} = cosθ + i sinθ

Permutations (^nP_r)

^nP_r = n! / (n - r)!

Combinations (^nC_r)

^nC_r = n! / [r! (n - r)!]

Symmetry Property

^nC_r = ^nC_{n−r}

Binomial Expansion

(a + b)ⁿ = ∑ ^nC_k a^{n−k} b^k

General Term

T_{r+1} = ^nC_r a^{n−r} b^r

Sum of First n Natural Numbers

\sum n = n(n + 1) / 2

Sum of Squares

\sum n² = n(n + 1)(2n + 1) / 6

Standard Trig Limit

lim_{x → 0} (sin x / x) = 1

Standard Exp Limit

lim_{x → 0} [(e^x − 1) / x] = 1

Parabola Equation

y² = 4ax

Ellipse Equation

x²/a² + y²/b² = 1