first, what does this have to do with differential equations? secondly, are you sure the /x should be there? example, can be worked out, but has no solution in elementary functions. it's an elliptical integral i believe

also, be careful with what your TA says and make sure all the signs are right. for instance, -ln(a/b) = ln(b/a). so make sure you're not leaving off a minus sign or something