# What is the identity matrix of size 4?

##### 1 Answer

Sep 13, 2014

The identity matrix of a 4x4 matrix is:

To find the identity matrix of an nxn matrix you simply put 1's for the main diagonal (from the top left to the bottom right http://en.wikipedia.org/wiki/Main_diagonal) of the matrix, and zeroes everywhere else (so in the "triangles" below and above the diagonals)