1) y=cos^2(x/2)-sin^2(x/2)=cos(2*x/2)=cosx F(X)=sinx +C
2) y=1-2sin^2(x/2)=cos(2*x/2)=cosx F(x)=sinx +C
1) y=cos^2(x/2)-sin^2(x/2)=cos(2*x/2)=cosx F(X)=sinx +C
2) y=1-2sin^2(x/2)=cos(2*x/2)=cosx F(x)=sinx +C