Найти производные 1. y=sinx/e^x 2.y=cos^4*2x 3.y=tg(4x-5)

1. y' = [sinx/(e^x)]' = e^x*cosx -sinx*e^x/(e^2x)=(cosx-sinx)/e^x
2. y' = [cos^4(2x)]' = 4cos^3(2x) * -sin(2x) *2 = -8cos^3(2x)*sin(2x)
3. y' = [tg(4x-5)]' = 4/cos^2(x)