# How do i differentiate #xe^(xy)cos(2x)# with respect to x??

##### 1 Answer

Feb 5, 2015

This is actually a multiplication rule within a multiplication rule.

I'm going to evaluate it as:

Remember the rule for multiplication:

first(derivative of the 2nd) + second(derivative of the first)

You also need to remember that you must take the derivative of the "inside" of the cos.

We can factor out