Cos ^ 2 (2x) derivation It's all - 2 (cos2x * sin2x) The answer in the book is - 2sin4x. How did you get it

Cos ^ 2 (2x) derivation It's all - 2 (cos2x * sin2x) The answer in the book is - 2sin4x. How did you get it


【cos^2(2x) 】'
=2cos(2x)*(cos2x)'
=2cos2x*(-2sin2x)
=-4sin2x*cos2x



Quick... Derivation y = 2x times cos (2x + π / 6)


y'=(2x)' cos(2x+π/6)+2x[cos(2x+π/6)]'
=2cos(2x+π/6) - 4xsin(2x+π/6)