# What is #f'(-pi/3)# when you are given #f(x)=sin^7(x)#?

##### 2 Answers

It is

**Method**

It is very useful to re-write this as

Use the power rule and the chain rule (This combination is often called the generalized power rule.)

For

In other notation

In either case, for your question

You could write

At

Now,

but remember

You Have The Honor To Simplify

NOTE:

{

wondering why im doing all this "let stuff" ?

the reason is there are more than one function in

** there's :

so to find the

AND the

that's why i need to let

then let

}