# Dimensions of a Matrix

Let V = M_2,2 be the space of all 2x2 matrices, and W be the subspace of all A belonging to M_2,2 such that AJ = JA where

J = [ 1, 1

0, 1 ]

Then, the dimension of W is

A) 0

B) 1

C) 2

D) 3

E) 4

https://brainmass.com/math/matrices/dimensions-matrix-517987

#### Solution Preview

The dimension of W is 2, so C) is correct.

We can assume that

A=[a b]

...

#### Solution Summary

Dimensions of a matrix are discovered.

$2.19