# How do you differentiate #f(x)=ln(tanx)# using the chain rule?

##### 1 Answer

Dec 8, 2015

#### Explanation:

You need the chain rule for composite functions, and the rule states that

So, you differentiate the outer function, leaving its argument untouched, and then you multiply by the derivative of the inner function.

In your case, the outer function is

So, the derivative of the outer function is

On the other hand, the derivative of

So,

And since