what is sec2x = 2

sec(2x)  =  2   --->   2x  =  sec^-1(2)   --->   x  =  sec^-1(2) / 2   --->   x  =  60°  or 300°  

   (plus/minus whole number multiples of 360° and )

This problem can be changed into a cos problem:  sec(2x)  =  2   --->   cos(2x)  =  1/2    

--->   2x  =  cos^-1(1/2)   --->   x  =  cos^-1(1/2)  / 2   --->   x  =  60°  or 300°      

   (plus/minus whole number multiples of 360°)