[SOLVED] Induced matrix norms

Consider the matrix

$\displaystyle

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

$

Consider the matrix norm $\displaystyle ||\cdot||_{ind}$ induced by the $\displaystyle 1-norm$ on the domain and the $\displaystyle \infty-norm$ on the range. Applied to A, we have that:

a) $\displaystyle ||A||_{ind}=5$

b) $\displaystyle ||A||_{ind}=\sqrt{15}$

c) $\displaystyle ||A||_{ind}=4$

d) $\displaystyle ||A||_{ind}=3$

thanks again.

I think I found the solution

I found a paper by Drakakis, K.

International Journal of Algebra, Vol. 3, 2009, no. 5, 231 - 240

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

I used this formula and came up with the answer 3.

If there are no objections I will mark this one solved.

Bucephalus