f(x)=cos(2x-x/3)+2sin(x-π/4)sin(x+π/4)sin(x+π/4)化简.

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/30 02:53:54
f(x)=cos(2x-x/3)+2sin(x-π/4)sin(x+π/4)sin(x+π/4)化简.
x)KӨдM/0Э76*Ө=ߠo fj3L{A&H`}03 l(vē={{6c=9@U kí( d֠bVa4E%PaLaQ)00T&Z-C}#`a LqrrP{!jj_\gA͒

f(x)=cos(2x-x/3)+2sin(x-π/4)sin(x+π/4)sin(x+π/4)化简.
f(x)=cos(2x-x/3)+2sin(x-π/4)sin(x+π/4)sin(x+π/4)
化简.

f(x)=cos(2x-x/3)+2sin(x-π/4)sin(x+π/4)sin(x+π/4)化简.
似乎是f(x)=cos(2x-π/3)+2sin(x-π/4)sin(x+π/4)
=cos(2x-π/3)+2sin(x-π/4)cos[π/2-(x+π/4)]
=cos(2x-π/3)+2sin(x-π/4)cos(π/4-x)
=cos(2x-π/3)+2sin(x-π/4)cos(x-π/4)
=cos(2x-π/3)+sin[2(x-π/4)]
=cos2xcosπ/3+sin2xsinπ/3+sin(2x-π/2)
=cos2x*1/2+sin2xsinπ/3-cos2x
=sin2xsinπ/3-cos2x*1/2
=sin2xsinπ/3-cos2x*cosπ/3
=-cos(2x+π/3)