Question

f(x)=tan²x,find f'(x) for it.

Answer 1

It is given that f(x) = tan²x

we know, derivative of tanx is sec²x .
I means , d(tanx)/dx = sec²x

now, f(x) = tan²x
differentiate both sides with respect to x,
df(x)/dx = d(tan²x)/dx
f'(x) = 2tanx × d(tanx)/dx
= 2tanx.sec²x

hence, f'(x) = 2tanx.sec²x