Question

Let (9,10) be a point on the terminal side of theta. Find cos theta, sec theta, and cot theta.

Answer 1

http://www.mathopenref.com/trigterminalside.html
Ok so you have a triangle with 9 being the x component and 10 being the y component.
Pythagorean Theorem yields sqrt(9^2 + 10^2) = 13.454
so the hypotenuse is 13.454 units long.
cos theta = adj/hyp = 9/13.454
sec theta = hyp/adj = 13.454/9
cot theta = adj/opp = 9/10
You can simplify if you like