[JEE Main 2015] the sum of the coefficients of the integral powers of x in 1 2
The sum of the coefficients of the integral powers of $x$ in $(1-2\sqrt x)^{50}$ is
(a) $\dfrac{3^{50}-1}2$
(b) $\dfrac{2^{50}+1}2$
(c) $\dfrac{3^{50}+1}2$
(d) $\dfrac{3^{50}}2$
1 Answer
VAVidaara Admin
✓ Vidaara Team
✓ Accepted
· 2d ago
▲ 0
Correct answer: (c) $\dfrac{3^{50}+1}2$
Integral powers need $k$ even: $\frac12\big[(1-2)^{50}+(1+2)^{50}\big]=\frac{1+3^{50}}2$.
JEE Main 2015 · 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.