Posted by Ted on Monday, November 17, 2008 at 9:36pm.
cos2x(2cosx+1)=0
Solve for x.

Trig  Ted, Monday, November 17, 2008 at 9:51pm
Please.

Trig  Ted, Monday, November 17, 2008 at 10:10pm
(2cos^2x1)(2cosx+1)=0
^
[Double angle identity]
Now I'm stuck. 
Trig  IHaveScabs, Saturday, October 12, 2013 at 11:14am
hey ted did you ever figure that out because if so tell me tell me now plz i need this very much