triangle RST is a right triangle with m<S=90 degrees
RS=24 cosR=12/13 Find Cot R
5/12
5/12
12/5

triangle RSt is a right triangle with m<S=90 degrees
Rs=48 cos R=24/25 Find sin R

7/24
25/24
7/25 

solve the equation for 0 ≤theta ≤2 pie   : sin theta cos theta - cos theta=0
0,pie
pie/2,3pie/2
pie/2,-1