# Math Help - Derivative help?

1. ## Derivative help?

Hello! Can anybody help me and tell me what the derivative of (6x)^-2 is? Thanks! I'm having a brain fart

2. ## Re: Derivative help?

Originally Posted by camjenson
Hello! Can anybody help me and tell me what the derivative of (6x)^-2 is?
$D_x \left[ {\left( {6x} \right)^{ - 2} } \right] = - 12\left( {6x} \right)^{ - 3}$.

BTW: Your brain cannot to that.

3. ## Re: Derivative help?

Hello, camjenson!

Can anybody tell me what the derivative of $(6x)^{-2}$ is?

If you can't handle the Chain Rule,
. . you can write: . $y \;=\;(6x)^{-2} \;=\;6^{-2}x^{-2} \;=\;\tfrac{1}{36}x^{-2}$

Then: . $y' \;=\;\tfrac{1}{36}\left(\text{-}2x^{-3}\right) \;=\;-\tfrac{1}{18}x^{-3} \;=\;-\frac{1}{18x^3}$