## Invertible Idempotent Matrix is the Identity Matrix

## Problem 1

A square matrix $A$ is called **idempotent** if $A^2=A$.

Show that a square invertible idempotent matrix is the identity matrix.

Add to solve laterA square matrix $A$ is called **idempotent** if $A^2=A$.

Show that a square invertible idempotent matrix is the identity matrix.

Add to solve later