解
2(1/2cos2x+√3/2sin2x)
=2(cos2xsinπ/6+cosπ/6sin2x)
=2sin(2x+π/6)

是对的
asinx+bcosx
=√a²+b²sin(x+t)
tant=b/a
也可以用这个公式1/2cos2x+√3/2sin2x怎么变成cos2xsinπ/6+cosπ/6sin2x∵sinπ/6=1/2,cosπ/6=√3/2cos2xsinπ/6+cosπ/6sin2x怎么变成sin(2x+π/6)有公式呗sin(2x+π/6)=sin2xcosπ/6+cos2xsinπ/6