I am confused as to what integral you want to be solved. You need to write the integral function in a form like (*integrand*) eq = 1; (*limits*) limits = {x, 2 - Sqrt[2], 1}; result = Integrate[eq, limits] So, I don't understand your question - are you trying to integrate it twice? eq = 1; limits = {y, 1/2 - 1/2 Sqrt[(-4 + 8 x - 4 x^3 + x^4)/((-2 + x)^2 x^2)], 1/2 + 1/2 Sqrt[(-4 + 8 x - 4 x^3 + x^4)/((-2 + x)^2 x^2)]}; result1 = Integrate[eq, limits] limits2 = {x, 2 - Sqrt[2], 1}; NIntegrate[result1, limits2]