TRIG
posted by John on .
if sin s = 5 /13
and sin t 3/5
s is in QIII
t is in QIV
find tan (st)
i got that tan (st)= 56/53
is that right? can someone check my work?

If sin s = 5/13, and it is in the third quadrant, cos s = 12/13
s = 202.620 degrees
If sin t is 3/5, and t is in the fourth quadrant, cos t = 4/5.
t = 323.130 degrees
tan (st) = sin (st)/cos(st)
= [sin s cos t  sin t cos s]/
[cos s cos t + sin s sin t]
Crunch the numbers. You should get a rational fraction, but your 53 in the denominator looks fishy.
You answer should be 56/33.