# Linear Algebra (Matrices)

1. May 16, 2007

### ssb

1. The problem statement, all variables and given/known data

Lets say A = a matrix.

What is meant by the question $$A - I_3$$ ???

I dont understand what the I means and im only given one matrix.... a 3x3 matrix listed as A

Last edited: May 16, 2007
2. May 16, 2007

### Dick

I_3 is a 3x3 identity matrix - ones down the diagonal and zeros elsewhere.