sin(a+π/3)+2sin(a-π/3)-根号3cos(2π/3-a)
问题描述:
sin(a+π/3)+2sin(a-π/3)-根号3cos(2π/3-a)
答
sin(a+π/3)+2sin(a-π/3)-根号3cos(2π/3-a)=sinacosπ/3+cosasinπ/3+2sinacosπ/3-2cosasinπ/3-√3cosacos2π/3-√3sinasin2π/3=sina*1/2+cosa*√3/2+2sina*1/2-2cosa*√3/2-√3cosa*(-1/2)-√3sina*√3/2=-...