1. The problem statement, all variables and given/known data Give a proof: Let C be a square matrix. Show if C^(k+1)=0, then I-C is nonsingular and (I-C)^-1=I+C+C^2+...+C^k. 2. Relevant equations I don't know. I can't find a theorm that will help me. 3. The attempt at a solution I know if a matrix is nonsingular, it has an inverse.