请帮我化简 y=Cos2x+SinxCosx

问题描述:

请帮我化简 y=Cos2x+SinxCosx

y=Cos2x+(1/2)(2SinxCosx)
=Cos2x+(1/2)Sin2x
=(根号5/2)sin(2x+φ) 且tanφ=2