函数f(x)=sinx^2+cos(x-π /3)^2的单调增区间是

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函数f(x)=sinx^2+cos(x-π /3)^2的单调增区间是

函数f(x)=sinx^2+cos(x-π /3)^2的单调增区间是
函数f(x)=sinx^2+cos(x-π /3)^2的单调增区间是

函数f(x)=sinx^2+cos(x-π /3)^2的单调增区间是
f(x)=sin²x+cos²(x-π/3)
=[1-cos(2x)]/2 +[1+cos(2x-π/3)]/2 /二倍角公式
=(1/2)[cos(2x-2π/3)-cos(2x)] +1
=(1/2)[cos(2x)cos(2π/3)+sin(2x)sin(2π/3) -cos(2x)]+1
=(1/2)[(-1/2)cos(2x)+(√3/2)sin(2x)-cos(2x)] +1
=(1/2)[(√3/2)sin(2x)-(3/2)cos(2x)]+1
=(√3/2)[(1/2)sin(2x)-(√3/2)cos(2x)]+1
=(√3/2)sin(2x -π/3) +1
2kπ-π/2≤2x-π/3≤2kπ+π/2 (k∈Z)时,(√3/2)sin(2x -π/3) +1单调递增,f(x)单调递增,此时
kπ-π/12≤x≤kπ+5π/12 (k∈Z)
函数f(x)的单调递增区间为[kπ-π/12,kπ+5π/12] (k∈Z)