# Thread: 2-norm and infinity norm releationship

1. ## 2-norm and infinity norm releationship

I am trying to understand how the 2-norm and ∞-norm are related on vectors. Basically I have the equations
||x||2 ≤ a ||x||∞ and ||x||∞ ≤ b ||x||2
and I need to determine the constants a and b that relate these two norms. Can anyone provide some insight?

2. Hello,

On what space are we talking?
$l^2$ ?
$\mathbb{R}^n$ ?