trig
posted by k .
find the exact value of sin(u+v) given that sin u=3/5 and sin v= 15/17

just drag out your good old trig identities:
sin^2 a + cos^2 a = 1
You have a 345 and a 81517 triangle.
You could figure that out using the formula above.
Next:
sin(u+v) = sinu cosv + cosu sinv
sin(u+v) = 3/5 * 8/17 + 4/5 * 15/17
and I guess you can take it from there . . .