Quote by Chen
Thanks for your tips. I was able to get the equation to the form:
[tex]a^2 cos(ax) + b^2 cos(bx) = c[/tex]
where a,b,c are different constants, but still irrational. Any ideas from here? :)
Thanks!

I spent halfanhour trying to solve it for x. But I couldn't.
I am starting to think that there is no closed form solution to this equation. Anyone else share the same thought?