Posted by Amir on Monday, January 23, 2012 at 10:01am.
prove that (cotx+tanx)(cotxtanx) = 1/(sin^2 x)  1/(cos^x)

matj  Damon, Monday, January 23, 2012 at 10:10am
cot^2  tan^2
cos^2/sin^2  sin^2/cos^2
(1  sin^2)/sin^2  (1cos^2)/cos^2
1/sin^2  1  1/cos^2 + 1
1/sin^2  1/cos^2