Question

F(x) = tan 2x , f'(x) = ....

Answer 1

Using the chain rule : $[\tan(2x)]'=(2x)'\tan'(2x)=\frac{2}{\cos^2(2x)}$

Answer 2

$f(x)=\tan 2x\\ f'(x)=\sec^2 2x\cdot2=2\sec^2 2x$