Euler Phi Function of 5
Jump to navigation
Jump to search
Theorem
- $\map \phi 5 = 4$
where $\phi$ denotes the Euler $\phi$ function.
Proof
From Euler Phi Function of Prime:
- $\map \phi p = p - 1$
As $5$ is a prime number it follows that:
- $\map \phi 5 = 5 - 1 = 4$
$\blacksquare$