Question

In the expansion of $\frac{a + bx}{e^{x}}$, the coefficient of $x^{r}$ is.

• A. $\frac{a - b}{r!}$
• B. $\frac{a - br}{r!}$
• C. $( - 1)^{r}\frac{a - br}{r!}$
• D. None of these

Answer 1

Answer: (C)

$( - 1)^{r}\frac{a - br}{r!}$

Answer 2

$\frac{1}{2} + \frac{1}{3}.\frac{1}{2^{3}} + \frac{1}{5}.\frac{1}{2^{5}} + .....\infty$

$\log_{e}\sqrt{\frac{3}{2}}$

The coefficient of

$x ^ { r }$ $\log_{e}\sqrt{\frac{1}{2}}$.