已知函数f(x)=sin^2x+根号3sinx×sin(x+π/2)(1)f(x)的最小正周期(2)求f(x)的单调递增区间(3)求f(x)在区间【0,2π/3】的取值范围

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已知函数f(x)=sin^2x+根号3sinx×sin(x+π/2)(1)f(x)的最小正周期(2)求f(x)的单调递增区间(3)求f(x)在区间【0,2π/3】的取值范围
已知函数f(x)=sin^2x+根号3sinx×sin(x+π/2)
(1)f(x)的最小正周期
(2)求f(x)的单调递增区间
(3)求f(x)在区间【0,2π/3】的取值范围

已知函数f(x)=sin^2x+根号3sinx×sin(x+π/2)(1)f(x)的最小正周期(2)求f(x)的单调递增区间(3)求f(x)在区间【0,2π/3】的取值范围
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(1)f(x)的最小正周期 π
f(x)=sin^2x+√3sinx×sin(x+π/2)
=(1-cos2x)/2 -√3sinxcosx
=1/2 -(cos2x)/2 -√3/2 sin2x
=1/2 -sin(2x+π/6)
(2)求f(x)的单调递增区间:[kπ+π/6,kπ+2π/3]
2kπ+π/2≤2x+π/6≤2kπ+3π/2 得:kπ+π/6≤x≤kπ+2π/3
(3)求f(x)在区间【0,2π/3】的取值范围
f(x)在区间【0,π/6】单调递减,取值范围:[-1/2,0]
f(x)在区间【π/6,2π/3】单调递增,取值范围:[-1/2,3/2]
所以:f(x)在区间【0,2π/3】的取值范围:[-1/2,3/2]
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