sin(pie-x)-sin(pie of two+x)= sinx-cosx。

Because the terminal edge of angle X passes through point p( 1, root number 3).

So sinx-cosx=[ root number (3)- 1]/2.

2

S∈{S|S=2k pie+pie /3，k∈z}

2cos2x+5sinx-4=-4sin^2x+5sinx-2

Then treat this formula as a system of binary linear equations.