shiwwfj
春芽
共回答了21个问题采纳率:90.5% 举报
1.T=π
fx=2cosxsin(x+π/3)-√3sin^2x+sinxcosx
=cosxsinx+√3cos^2x-√3sin^2x+sinxcosx
=2sinxcosx +√3cos2x
=sin2x+√3cos2x
=2(1/2sin2x+√3/2cos2x)
=2sin(x+π/3)
所以T=π
2.fx=2sin(x+π/3)
因为x∈[0,π/4]
所以x+π/3∈[π/3,7π/12]
所以sin(x+π/3)∈[√3/2,1]
所以fx=2sin(x+π/3)∈[√3,2]
1/2不属于)[√3,2]
所以不存在x使得fx=1/2
1年前
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