But you have already solved the problem! All you have to do is to take the arccos of the Left Hand Side and that gives you =Pi / 12, which equals The Right Hand Side of =Pi / 12.
LHS =Take the square root of 3 =[1.7320508.... / 2 + 1] / 2 =0.9330127018.....Now take the square root of this: Sqrt(0.9330127018) =0.9659258262890. Then take the arccos of this in radians:arccos(0.9659258262890) =0.26179938779914943653855361527329 = Pi / 12. And that is it !.
