We square both sides



We use the Pythagorean trig identity: 
 to write
the right side:







You finish. That gives you two values for x in [0,2p).  
But since I squared both sides, you must check for 
extraneous solutions. 

--------------------------



Factor out common factor of tan(x)





You finish by solving tan(x)=0 for x.
But remember that sec(x) always has
absolute value greater than or equal to 1.

Edwin