1/2cos方x-sinxcosx-1/2sin方x

问题描述:

1/2cos方x-sinxcosx-1/2sin方x
求最小正周期

=1/4cos2x+1/4-1/2sin2x+1/4cos2x-1/4
=1/2cos2x+1/2sin2x
=根号下1/2 sin(2x+pi/4)