Q. The coefficient of $x^{4}$ in $(1 - x)^{- 3}$ (where $∣ x ∣ < 1)$ is

390 242 Binomial Theorem Report Error

A

10

B

15

C

9

D

6

Solution:

General term in the expansion of $(1 - x)^{- 3}$ is $^{3 + r - 1} C_{r} x^{r} =^{r + 2} C_{r} x^{r}$