求证 cos(A)+ 根号3sin(A)=2sin(π/6+A)

问题描述:

求证 cos(A)+ 根号3sin(A)=2sin(π/6+A)

右边2sin(π/6+A)=2sin(π/6)cosA+2sinAcos(π/6)=cosA+根号3sin(A)=左式.得证#