已知函数f(x)=sin2x+2sinxcosx-cos2x ()

问题描述:

已知函数f(x)=sin2x+2sinxcosx-cos2x ()

f(x)=sin2²x+2sinxcosx-cos²x
=2sinxcosx-(cos²x-sin2²x)
=sin(2x)-cos(2x)
=√2sin(2x-π/4)