# Thread: Clarification on absolute value notation

1. ## 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?

2. ## Re: Clarification on absolute value notation

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?
We can argue about this. But yes, it is 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.

3. ## Re: Clarification on absolute value notation

Yea, I was thinking along those lines, but I felt a bit unsure about whether I was missing something. Thanks!