1. The problem statement, all variables and given/known data hi guys ,, how are you all ,, i got another problem -_- integral(1/sqrt(4 x-x^2), x) 2. Relevant equations 3. The attempt at a solution i have no idea , i tried and lift it up and make it (4x-x^2)^-0.5 and i even took x as common factor x^-0.5 * (4-x)^-0.5 but still couldn't do anything next ,, any ideas ??