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问题: 三角函数。。

设f(x)=2cosxsin(x+Π/3)-√3(sinx)^2+sinxcosx
求函数的最小正周期。

解答:

f(x)=2cosxsin(x+Π/3)-√3(sinx)^2+sinxcosx
=2cosxsin(x+Π/3)+sinx(cosx-√3sinx)
=2cosxsin(x+Π/3)+2sinx[cosx(1/2)-sinx(√3/2)]
=2cosxsin(x+Π/3)+2sinxcos(x+Π/3)
=2[cosxsin(x+Π/3)+sinxcos(x+Π/3)]
=2sin[x+(x+Π/3)]
=2sin(2x+Π/3)
所以,函数的最小正周期T=2Π/2=Π