The exercice that my professor gave me :
Calculate the geodesics equations of a torus with a lagrangien equation, i did the calculation in the final i got this elliptic integral,he asked us to calculate it. I m thinking of changing variable but i don t know which one exactly!!
$\int\frac{1}{(2+\cos(v))\sqrt{((2+\cos(v))^2-\alpha^2)}} dv$
A hint can help!
thank you for help! :)