Draw your triangles in standard position. Then it is clear that
sinx = -4/5
tanx = 4/3
cosy = -√77/9
tany = -2/√77
Now just plug the needed values into the identities you have
Suppose that cosx= -3/5 and x is in the third quadrant, and that siny= 2/9 and y is in the second quadrant. Find the exact values
1). tan(y/2)
2). cos(x+y)
3). tan(x+y)
1 answer
2 answers