# Math Help - Differentiation - I thought I had finally got it, but im stuck again!

1. ## Differentiation - I thought I had finally got it, but im stuck again!

Ok, the question is:

Differentiate: five over the square root of four + x

2. ## Re: Differentiation - I thought I had finally got it, but im stuck again!

$\frac{5}{\sqrt{4+x}}=5(4+x)^{-1/2}$

Use the chain rule.

3. ## Re: Differentiation - I thought I had finally got it, but im stuck again!

thanks, i got that far. But its after that that I get lost.
The answer says -5 over 2 times the square root of 4 + x cubed

thankyou!