已知f(x)cos(2x-派/6)-cos(2x+派/6)+2cosx平方
问题描述:
已知f(x)cos(2x-派/6)-cos(2x+派/6)+2cosx平方
答
f(x)=cos(2x-π/6)-cos(2x+π/6)+2cos²x=cos2xcos(π/6)+sin2xsin(π/6)-[cos2xcos(π/6)-sin2xsin(π/6)]+2cos²x=2sin2xsin(π/6)+2cos²x=sin2x+2cos²x=sin2x+cos2x+1=√2sin(2x+π/4)+1如果不...