9:42

(n-1)!+1 = n^2

20:37

Integre x^-x dx

16:47

Prove que n^3 + 11n é divisível por 6.

10:04

A Nice Geometric Olympiad Puzzle l Find the Height of this Triangle l Math Olympiad Challenge

8:02

Don't panic. There are two basic strategies to solve questions like this