# If #f(x)= cos(-2 x -1) # and #g(x) = 3x^2 -5 #, how do you differentiate #f(g(x)) # using the chain rule?

##### 1 Answer

May 10, 2016

#### Explanation:

The chain rule says that the derivative of a compound function like

or, the derivative of the whole thing is the derivative of the inside times by the derivative of the outside (with the inside left the same).

The question gives us the functions, so differentiate them normally, like so

We can put these functions into the chain rule equation,