(√3cosA-1/2)^2+(√3sinA+√3/2)^2=(cosA+√3/2)^2+(sinA-3/2)^2,a等于?

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(√3cosA-1/2)^2+(√3sinA+√3/2)^2=(cosA+√3/2)^2+(sinA-3/2)^2,a等于?
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(√3cosA-1/2)^2+(√3sinA+√3/2)^2=(cosA+√3/2)^2+(sinA-3/2)^2,a等于?
(√3cosA-1/2)^2+(√3sinA+√3/2)^2=(cosA+√3/2)^2+(sinA-3/2)^2,a等于?

(√3cosA-1/2)^2+(√3sinA+√3/2)^2=(cosA+√3/2)^2+(sinA-3/2)^2,a等于?
两边去括号得
3cos²A-√3cosA+1/4+3sin²A+3sinA+3/4=cos²A+√3cosA+3/4+sin²A-3sinA+9/4
合并、消除同类项后整理成
2cos²A-2√3cosA+2sin²A+6sinA-2=-2√3cosA+6sinA=0
两边除以4√3得
-1/2cosA+√3/2sinA=sin(-π/6)cosA+cos(-π/6)sinA=sin(A-π/6)=0
所以A=kπ+π/6 (k∈Z)