B Theorem: Suppose that A is a px p nonsingular matrix. Then the cost of computing the LU-decomposition A = P LU of A is p/3 - p/3 multiplications/divisions, and p/3 - p2/2+p/6 additions/subtractions. Use the formulas n(n + 1) 1 + 2 + ... + n = and 1+ 4 + ... +72 - n(n + 1)(2n +1) to prove this theorem. B Theorem: Suppose that A is a px p nonsingular matrix. Then the cost of computing the LU-decomposition A = P LU of A is p/3 - p/3 multiplications/divisions, and p/3 - p2/2+p/6 additions/subtractions. Use the formulas n(n + 1) 1 + 2 + ... + n = and 1+ 4 + ... +72 - n(n + 1)(2n +1) to prove this theorem