Question

Find the exact value of the trigonometric function given that
sin u = − 8/17 and cos v = − 3/5.
(Both u and v are in Quadrant III.)

cot(v − u)

Answer 1

cot(v-u) = (cotv cotu + 1)/(cotu - cotv)

= [(3/4)(15/8) + 1] / [(15/8) - (3/4)]
= (77/32) / (3/8)
= 77/12

Answer 2

I answered this question for a test and I got 40/43 as the cot since i did tan=(-4/5+15/8) and solved to get 43/40 and since cot is the reciprocal of tan I just flipped it over to get 40/43