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函数f(x)=2sin2x-2sinxcosx-根号3cos2x求最小正周期和最值

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函数f(x)=2sin2x-2sinxcosx-根号3cos2x求最小正周期和最值
f(x)=2sin2x-2sinxcosx-√3cos2x
=2sin2x-sin2x-√3cos2x
=sin2x-√3cos2x
=2(1/2sin2x-√3/2cos2x)
=2sin(2x+ψ)
T=2π/2=π
f(x)max=2 f(x)min=-2
再问: 当x=多少时有最大最小
再答: =2sin(2x+ψ)=2sin(2x-π/3) 2x-π/3=π/2+2kπ 2x=5π/6+2kπ x=5π/12+kπ k=0,1,2……有最大值 2x-π/3=-π/2+2kπ 2x=-π/6+2kπ x=-π/12+kπ k=0,1,……2有最小值.