Which expression completes the identity cos u sin v= ? A. [sin(u + v) + sin(u – v)]
B. (cos(u – v) + cos(u + v)]
C. 1 (sin(x + v) – sin(u – v)]
D. (cos(u – v)(cos(u – v) – cos(u + v)]

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right