Question

How do you differentiate `f(x)=tan(3x)-cot(3x)`?

Answer 1

`f'(x)=3/(sin^2(3x)*cos^2(3x))`

Explanation:

Note that

`(tan(x))'=1/cos^2(x)`
and

`(cot(x))'=-1/sin^2(x)`
then we get
`f'(x)=3/cos^2(3x)+3/sin^2(3x)`