Second norm of matrix

[niko2000]

Hi,
I have forgotten the formula for calculating the second norm of matrix. Does anyone know the formula?
Regards,
Niko

[Hurkyl]

Are you talking about the norm usually written as ||A||_2? You simply consider the (mxn) matrix as an mn-tuple: the square of the norm is the sum of the squares of the entries.

[mathwonk]

this is also called the pythagorean theorem. i'll bet you haven't really forgotten it. almost no one ever does: a^2 + b^2 = c^2.