How do you differentiate # f(x)=cot(x)cos(x)# using the product rule?
This is more a pointer in the correct direction:
Once you know that
and you combine it with
You are off to a flying start. Just substitute and play until you find a solution:
As a check I put it into Maple which gave:
Maple outputs are sometimes a little 'Maple'ish' so need to be translated.
so you may be able to use: