Question 972524
Assuming an angle in Quadrant I, find the exact value of 
cos(cot^-1(12/5)).
Problem is to find the cos of an angle (x) whose cot is (12/5)
That is, cotx=12/5 (working with a (5-12-13) reference right triangle in quadrant I)
cos(cot^-1(12/5))= cos x=12/13