Question

The coefficient of $x^{3}$ in the expansion of $(1 - \frac{3}{4}x)^{\frac{1}{2}}$ is

• A. $\frac{27}{1024}$
• B. $\frac{-27}{1024}$
• C. $\frac{81}{1024}$
• D. $\frac{-81}{1024}$

Hint:

For $(1-x)^{n}$ with $n=1/2$, the terms alternate signs. The third power ($x^{3}$) will have a negative coefficient.

Answer 1

The Correct Option is B