Question #36b27

1 Answer
Feb 20, 2017

120/169

Explanation:

tan t = 5/12 --> cot t = 12/5
Use trig identity:
sin^2 t = 1/(1 + cot^2 t)\sin^2 t = 1/(1 + 144/25) = 25/169
sin t = +- 5/13
Since t is in Quadrant 3, there for, sin t is negative
sin t = - 5/13.
Find cos t.
co^2 t = 1 - sin^2 t = 1 - 25/169 = 122/169
cos t = - 12/13 (t in Quadrant III)
sin 2t = 2sin t.cos t = 2(-5/13)(-12/13) = 120/169