答:
f(x)=sinxcosx(x-π/4)+sin(π/2+x)sin(x-π/4)
=sinxcosx(x-π/4)+sin[π-(π/2-x)]sin(x-π/4)
=sinxcosx(x-π/4)+sin(π/2-x)sin(x-π/4)
=sinxcosx(x-π/4)+cosxsin(x-π/4)
=sin(x+x-π/4)
=sin[2(x-π/8)]
=sin[2(x-π/8)]
选择D
答:
f(x)=sinxcosx(x-π/4)+sin(π/2+x)sin(x-π/4)
=sinxcosx(x-π/4)+sin[π-(π/2-x)]sin(x-π/4)
=sinxcosx(x-π/4)+sin(π/2-x)sin(x-π/4)
=sinxcosx(x-π/4)+cosxsin(x-π/4)
=sin(x+x-π/4)
=sin[2(x-π/8)]
=sin[2(x-π/8)]
选择D