Recently, there is a funny photo circulates in the WeChat.

As one can see, the integration is complicated, and it really got me. I have contacted two other friends for advice. However, we both lost the ability to compute this integration manually.

I tried with Sympy in IPython. Still, we got no answer.

Finally, one of my colleges told me that it obviously is zero. Because the function to be integrated is an odd function and the limits are symmetric.

I drew all functions from basics with SymPy and IPython. They all make sense. Only the integration can not be done.

The calculation in the github: http://nbviewer.jupyter.org/github/quxiaofeng/quxiaofeng.github.io/blob/master/ipynb/WiFi-pass.ipynb