Question

How do you find the derivative of #cos^2x-sin2x?

Answer 1

`d/dxf(x)=-(sin2x+2cos2x)`

Explanation:

We find the derivative using function of a function concept.

As `f(x)=cos^2x-sin2x`

`d/dxf(x)=2cosx*(-sinx)-cos2x*2`

= `-2sinxcosx-2cos2x`

= `-(sin2x+2cos2x)`