# What are the critical points of # f(x) = (x - 3sinx)^4 -xcosx#?

##### 1 Answer

Feb 26, 2018

Critical Points are where the derivative is equal to 0.

But we need to find the derivative. In order to do so, I'll split up

PART 1:

Let's apply the Chain Rule.

PART 2:

Let's apply the Product Rule.

Now all you have to do is set that equal to 0:

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