sin(x±y)=sin(x)⋅cos(y)±cos(x)sin(y) \sin(x \pm y)=\sin(x) \cdot \cos(y) \pm \cos(x) \sin(y) sin(x±y)=sin(x)⋅cos(y)±cos(x)sin(y)
cos(x±y)=cos(x)⋅cos(y)∓sin(x)⋅sin(y) \cos(x \pm y) = cos(x)\cdot \cos(y) \mp \sin(x)\cdot \sin(y) cos(x±y)=cos(x)⋅cos(y)∓sin(x)⋅sin(y)
