Recall your sum-to-product identities:
sinA + sinB = 2 sin(A+B)/2 cos(A-B)/2
cosA + cosB = 2 cos(A+B)/2 cos(A-B)/2
That should get you started.
If sinA + sinB = a and cosA + cosB = b, find the value of tanA-B/2
3 answers
a/b is a value of tan[A-B/2]
Galat answer h chutiye