根号3/2sin2x-1+cos2x/2-1/2

问题描述:

根号3/2sin2x-1+cos2x/2-1/2
合一公式怎么解?

(√3/2)sin2x-1+(1/2)cos2x-1/2
=cos(30)sin2x+sin30cos2x-3/2
=sin(2x+30)-3/2