Now this becomes pretty straightforward. What is the antiderivative of all of this business? And we've done very similar things like this multiple times already. This is going to be equal to pi times the natural log, the natural log of the absolute value of u, so that we can handle even negative values of u, the natural log of the absolute value of u plus c, just in case we had a constant factor out here, plus c. And we're almost done. We just have to unsubstitute for the u. U is equal to natural log of x. So we end up with this kind of neat looking expression. This entire indefinite integral we have simplified, we have evaluated it.