6. Monthly mortgage payments f(A, r), (in dollars) for a 30-year fixed-rate mortgage are a function of the interest rate, r (percent), and the loan amount, A (dollars). Interest Rate (%) 4 5 6 7 $100000 477.42 536.82 599.55 665.30 Loan Amount $150000 716.12 805.23 899.33 997.95 $200000 954.83 1073.64 1199.10 1330.60 $250000 1193.54 1342.05 1498.88 1663.26 (a) (5 points) Approximate the partial derivative fA(150000, 5) using values from the table. Show your work. Round to 3 decimal places. (b) (5 points) Approximate the partial derivative fr(150000, 5) using values from the table. Show your work. Round to 3 decimal places