You may have heard a saying that any paper cannot be folded more than 7 times. This video shows that it is possible. In fact, you can fold 11 times! But the paper they are using is as large as a football field, while the original saying is that, you can't fold an A4 paper more than 7 times. It is still an interesting video to watch.

This is a short how to about how to sum sin(n q) and cos(n q).