One of the expressions below is equal to cos(A−B)\cos(A - B)cos(A−B) for all values of A A\,A and BBB.
Identify this expression.
Tick one box.
cosAcosB−sinAsinB\cos A\cos B - \sin A\sin BcosAcosB−sinAsinB
cosAcosB+sinAsinB\cos A\cos B + \sin A\sin BcosAcosB+sinAsinB
sinAcosB−cosAsinB\sin A\cos B - \cos A\sin BsinAcosB−cosAsinB
sinAsinB−cosAcosB\sin A\sin B - \cos A\cos BsinAsinB−cosAcosB