39 leta de an n x n matrix with real entries such that a? = a. if i denotes the n x n identity mati then show that rank(a - 1) = nullity (a). 39

39 LetA De an n x n matrix with real entries such that A? = A. If I denotes the n x n identity mati then show that rank(A - 1) = nullity (A). 39