sin(A±B)=sinAcosB±cosAsinB\sin(A \pm B) = \sin A \cos B \pm \cos A \sin Bsin(A±B)=sinAcosB±cosAsinB; cos2A=1−2sin2A\cos 2A = 1 - 2\sin^2 Acos2A=1−2sin2A; sin3A=3sinA−4sin3A\sin 3A = 3\sin A - 4\sin^3 Asin3A=3sinA−4sin3A.