Posted by john on Friday, May 27, 2011 at 10:14pm.
sec(90degrees theta)

trig  drwls, Friday, May 27, 2011 at 10:28pm
sec(90 theta) = 1/cos(90  theta)
= 1/(cos90 cos theta + sin 90 sin theta)
= 1/sin theta
= csc theta
You could get the same result by considering a right triangle. The sec of one acute angle is the csc of the other.