# Thread: [SOLVED] Induced matrix norms

1. ## [SOLVED] Induced matrix norms

Consider the matrix

$
A = \left[\begin{matrix}1 & -2\\1 & 3\end{matrix}\right]
$

Consider the matrix norm $||\cdot||_{ind}$ induced by the $1-norm$ on the domain and the $\infty-norm$ on the range. Applied to A, we have that:
a) $||A||_{ind}=5$
b) $||A||_{ind}=\sqrt{15}$
c) $||A||_{ind}=4$
d) $||A||_{ind}=3$

thanks again.

2. ## I think I found the solution

I found a paper by Drakakis, K.
International Journal of Algebra, Vol. 3, 2009, no. 5, 231 - 240

$||A||_{(1,\infty)}=^{max}_{(i,j)|\in\{1,.....,m\}\ times\{1,.....,n\}}|a_{ij}|$

I used this formula and came up with the answer 3.
If there are no objections I will mark this one solved.

Bucephalus