cos^2α+cos^2(α+π/3)-cosαcos(α+π/3)化简
问题描述:
cos^2α+cos^2(α+π/3)-cosαcos(α+π/3)化简
答
原式=cosα+(-1/2)cosα+(√3/2)sinα+(-1/2)cosa-(√3/2)sinα
=0
答
cos²α+cos²(α+π/3)-cosαcos(α+π/3)=1+[cos2α+cos2(α+π/3)]/2-cosαcos(α+π/3)=1+cos(2α+π/3)cos(π/3)-[cos(2α+π/3)+cos(π/3)]/2=1+[cos(2α+π/3)]/2-[cos(2α+π/3)...