The coefficient of xⁿ in (1+x)(1-x)ⁿ is (a) (-1)ⁿ⁻¹n (b) (-1)ⁿ(1-n) (c) (-1)ⁿ⁻¹(n-1)² (d) n-1

Correct answer: (b) (-1)ⁿ(1-n) (-1)ⁿ+n(-1)ⁿ⁻¹=(-1)ⁿ⁻¹(n-1)=(-1)ⁿ(1-n). JEE Main 2004 · Binomial Theorem — verified solution by the Vidaara Team.

JEE PYQ

[JEE Main 2004] the coefficient of x n in 1 x 1 x n is

VAVidaara Admin Asked 2d ago 0 views 1 answer

The coefficient of $x^n$ in $(1+x)(1-x)^n$ is

(a) $(-1)^{n-1}n$
(b) $(-1)^n(1-n)$
(c) $(-1)^{n-1}(n-1)^2$
(d) $n-1$

VAVidaara Admin ✓ Vidaara Team ✓ Accepted · 2d ago ▲ 0

Correct answer: (b) $(-1)^n(1-n)$

$(-1)^n+n(-1)^{n-1}=(-1)^{n-1}(n-1)=(-1)^n(1-n)$.

JEE Main 2004 · Binomial Theorem — verified solution by the Vidaara Team.

Log in to post your own answer or join the discussion.

No comments yet — start the discussion.