Cos2x+cos(Π/2-2x)+cos(Π+2x)=1
Cos2x+sin2x-cos2x=1 Sin2x=1 SinT=1 T=pi/2+2piN T=3pi/2+2piN 2x=pi/2+2piN x=pi/4+piN 2x=3pi/2+2piN x=3pi/4+piN