Without expanding $(1+x)^8$, find: The sum of the coefficients of its even powers of $x$. The su

Question

Without expanding $(1+x)^8$, find: The sum of the coefficients of its even powers of $x$. The sum of the coefficients of its odd powers of $x$. Explain why substituting $x=1$ and $x=-1$ is useful.

Accepted Answer

(a) Even-power sum $128$; (b) Odd-power sum $128$.

Binomial Theorem

Binomial Theorem

Solution:

Solution locked