Just testing whether Latex is working correctly: \[\frac{1}{2}\left( \int \exp\left\{ -\frac{x^2}{2}\right\} \, dx \right)^2 \approx 22/7\]
Here is a reference (MacKay 2003) and below is an animation:
References
MacKay, David JC. 2003. Information Theory, Inference and Learning Algorithms. Cambridge university press.