Find dy/dx for y = cos^4(2x)Step by step process

We have to find the derivative of y = (cos 2x)^4. We need
to use the chain rule here:

y' = [(cos
2x)^4]'

=> 4*(cos 2x)^(4 - 1)*(cos
2x)'

=> 4*(cos 2x)^3*(-sin
2x)*(2x)'

=> 4*(cos 2x)^3*(-sin
2x)*2

=> -8*(cos 2x)^3*(sin
2x)

The required derivative is -8*(cos
2x)^3*(sin 2x)