if sin theta equals 3/5 and theta is second quadrant angle find tan 2 theta.my ans. was 3.442 but is wrong can you correct and show work please. thank you so much.

3,4,5 right triangle in quadrant 2

cos t = -4/5
tan t = sin t/cos t = -3/4
tan 2 t = 2 tan t / (1-tan^2 t)
= 2 (-3/4) / (1-9/16)
= (-3/2)/(7/16)
= -3 /(7/8)
= -24/7
=-3.43