# Combinatorics involving negative rational n in nCr function

Hence, show that

$\frac{1}{\sqrt{1+x} }=\sum_{k=0}^{\infty }\binom{2k}{k}(\frac{-x}{4})^{k} $

## Answer

**Answers can be viewed only if**

- The questioner was satisfied and accepted the answer, or
- The answer was disputed, but the judge evaluated it as 100% correct.

Persimmonl

63

The answer is accepted.

Join Matchmaticians Affiliate Marketing
Program to earn up to 50% commission on every question your affiliated users ask or answer.

- answered
- 389 views
- $5.00

Knowledge of the gamma function is not assumed for this question.