# Question:

### If , Prove that . ……..[CBSC 2020]

## Solution:

Given,

Differentiating with respect to x, we have,

## Some other question:

**Q 2:** Find the value of at , if and . …….. [CBSC 2008, 2014]

Given,

Differentiating with respect to x, we have,

**Q 2:** Find the value of at , if and . …….. [CBSC 2008, 2014]