y=2sin²B+cos((2π/3)-2B)化简成y=Asin(ωx+φ)

问题描述:

y=2sin²B+cos((2π/3)-2B)化简成y=Asin(ωx+φ)
不对

y=2sin²B+cos((2π/3)-2B)
=(1-cos2B)-1/2cos2B+√3/2sin2B
=(-3/2cos2B+√3/2sin2B)+1
=√3(1/2sin2B-√3/2cos2B)+1
=-√3(sin(2B-π/3)+1为所求
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