1. The problem statement, all variables and given/known data Apologies for the vague title, I'm not reall sure what I'm look at here! I am doing some revision on solving the Friedmann equations, and in a lot of cases I end up having to integrate a function that looks like (xan - 1)-1/2 da = dt where a is a function of t, x is a constant, and I am trying to find an equation that describes a as a function of t. The first examples I have found have n = -1, n = -2 2. Relevant equations 3. The attempt at a solution I do have a solution for one of these in my lecture notes. In the case where dt = (xa-1-1)-1/2 the solution is given as t = x arctan ((xa-1-1)-1/2) - a1/2 (x - a)1/2 I would normally look on wolfram and work through their step-by-step solution to teach myself the method, but even wolfram can't answer this one! Any help would be much appreciated.