1. The problem statement, all variables and given/known data Given the matrix A= -1/5 7/5 -3/5 -4/5 find A43. 3. The attempt at a solution It's obvious that I can't go and actually compute A43 so there must be a more elegant way of doing this. The only notes I have on the subject is Ak=P-1DkP, where D is a diagonal matrix. However, I have no clue what P is supposed to to, nor why this would work in the first place.