sin(π+α)cos(
2
π
+α)−cos(2π+α)sin(
3π
−α)= =-sin \alpha *(-sin \alpha )-cos \alpha *(-cos \alpha )=sin^2 \alpha +cos^2 \alpha =1=−sinα∗(−sinα)−cosα∗(−cosα)=sin
α+cos
α=1
