Question

if y=cos2x then find dy/dx​

Answer 1

here your answer

= -2sin2x

hope it helps

Answer 2

Given

A function y = cos2x

To find

dy/dx

solution.

Here in question there is two functions cos and 2x

So we have differentiate it with chain rule..

$\frac{dy}{dx}=y'=\frac{d[cos2x]}{dx}$

Putting chain rule

$\implies\frac{dy}{dx}=y'=\frac{d[cos2x]}{d[2x]}\frac{d[2x]}{dx}$

$\implies\sf\frac{dy}{dx}=y'=(-sin2x)2$

Hence, differentiation is (-sin2x)2