# Thread: MC problem in Linear Algebra

1. ## MC problem in Linear Algebra

Hello,

I would like to know the answer of this multiple choice problem and I want to know the meaning of the two 2s next to the norm sign.

2. ## Re: MC problem in Linear Algebra

$||.||_p$ represents the p-norm.

In your case, this the two 2s represents the Euclidean norm, squared.

Reference: regression - What is the meaning of super script 2 subscript 2 within the context of norms? - Cross Validated

3. ## Re: MC problem in Linear Algebra

Where did you get this problem if you do not even know the notation? I cannot imagine a text book using the notation $||x||_2$ without first having defined it!

4. ## Re: MC problem in Linear Algebra

Originally Posted by HallsofIvy
Where did you get this problem if you do not even know the notation? I cannot imagine a text book using the notation $||x||_2$ without first having defined it!
No, it isn't from a text book ... I was just trying to solve some problems from an online website "brilliant"