E is irrational
From specialfunctionswiki
Theorem
The real number $e$ is irrational.
Proof
Videos
Proof - A Proof That "e" is Irrational (2009)
A proof that 'e' is irrational. (2012)
Best short proof that e is irrational (2013)
Proving e = 2.718... Is An Irrational Number (3 Methods) (2015)