Question

Find the derivative of 'tanx' by using first principle

Answer 1

let f(x)=tanx. thn. f(x+h)=tan(x+h)
use the formula f'(x)=limx->0f(x+h)-f(x)/h
..substitute the values in the formula u will get the answer as secx

Answer 2

The derivative of "tanx" is -----------
$\sec^{2} x$

Hope it will help you .