1. a) Prove the following holds for A A is a matrix [a b, c d] I is identity matrix. A^2 = (a+d)A-(ad-bc)I. b) Assuming ad-bc not equal to 0, use a) to obtain an expression for A^-1. 3. The attempt at a solution I proved the first equation, but I'm not seeing where it relates to the inverse. I know that ad-bc is the determinate. At first I was going to write A^-1 in terms of a,d,b,c in a matrix but I realize that this was done in class and its asking for an equation similar to the first one. I just want a couple of hints, because I'm stuck.