# Clarification on absolute value notation

• Nov 14th 2013, 07:25 AM
Scurmicurv
Clarification on absolute value notation
Not quite sure where this would fit best, but all uni calculus text books I've seen places this among the preliminaries, so it felt best here:

I've frequently seen both |a| and ||a|| to denote the absolute value of a value or a vector, and I was wondering if there is any deeper significance to this or if it's merely a matter of preference?
• Nov 14th 2013, 07:35 AM
Plato
Re: Clarification on absolute value notation
Quote:

Originally Posted by Scurmicurv
I've frequently seen both |a| and ||a|| to denote the absolute value of a value or a vector, and I was wondering if there is any deeper significance to this or if it's merely a matter of preference?

I will tell you why i prefer $\displaystyle \|\vec{a}\|$. First it is a norm really.
But also $\displaystyle \|\beta\vec{a}\|=|\beta|\cdot\|\vec{a}\|$. You see that distinguishes between the absolute value of a scalar and the norm of a vector.