# What is the derivative of sqrt(20-x^4?

##### 1 Answer
Feb 3, 2015

The answer is:

$y ' = \frac{1}{2 \cdot \sqrt{20 - {x}^{4}}} \cdot \left(- 4 {x}^{3}\right) = - \frac{2 {x}^{3}}{\sqrt{20 - {x}^{4}}}$.