# How do you find the derivative of #cos^2(x^2-2)#?

##### 1 Answer

#### Answer:

#### Explanation:

First of all define:

First use the chain rule to find the derivative of f(x):

Next split

In other words:

Now the product rule can be used to find the derivative of f(x)^2:

Using the trigonometric identity:

We finally gain:

SIn(x) is an odd function, so it's true that:

sin(x) = -sin(-x)

Which means we can also write the answer as:

Which removes the minus sign from the front, making the expression tidier.