# What is the identity matrix for subtraction?

May 28, 2015

Assuming we're talking about 2x2 matrices, the identity matrix for subtraction is the same as that for addition, namely:

$\left(0 , 0\right)$
$\left(0 , 0\right)$

The identity matrix for multiplication and division is:

$\left(1 , 0\right)$
$\left(0 , 1\right)$

There are analogous matrices of larger size, consisting of all $0$'s or all $0$'s except for a diagonal of $1$'s.