I have no idea how to approach these.. any help would be greatly appreciated. I can't seem to find this in the book either so if there are any links on the web that relate to these questions please let me know.. Thanks! Prove or disprove the following statements. I and 0 represent the identity and zero matrix of the same size as A. 1. If A is a matrix such that A^2 - 3A + 2I = 0, then A - 2I is invertible. 2. If A is a matrix such that A^2 - 5A + 5I = 0, then A - 3I is invertible. 3. If A is invertible, then A^2 + I is invertible. 4. Prove that there is no 5 by 5 matrix such at A^2 + I = 0.