Please answer only task 3 with matlab

Task 1: GUI Functions Create four external user-defined functions (each with 3 inputs, 1 output, a unique name, and thorough comments) corresponding to the four calculations described below. Test all of the functions with the test case shown below by calling each either from a separate script file or from function main. Calculate all variations of this test case where 3 of the 4 values are specified and the function produces the correct 4th value. Notice the equations use the monthly interest rate while your functions will have the annual interest rate as an input Variable Description PMonthly Payment A Principal Amount of Loan N Number of monthly payments | Annual Interest Rate i Monthly Interest Rate Test Case 399.25 17,000 48 6% (1/12)/100 Monthly Payment Amount P given A, N, and I iA Number of Payments N given P, A, and I: log(1- iA P) log(1+i) Principal Loan Amount A given P, N, and I: Interest Rate I given P, A, and N (Iterative Method There is no closed form interest rate formula. Instead, the Newton iterative method is used on a modified form of the basic loan equation. This method works by inserting an initial guess for the interest rate (1-10%), then looking at the difference between the calculated (inew), and the guessed interest (1) Task 1: GUI Functions Create four external user-defined functions (each with 3 inputs, 1 output, a unique name, and thorough comments) corresponding to the four calculations described below. Test all of the functions with the test case shown below by calling each either from a separate script file or from function main. Calculate all variations of this test case where 3 of the 4 values are specified and the function produces the correct 4th value. Notice the equations use the monthly interest rate while your functions will have the annual interest rate as an input Variable Description PMonthly Payment A Principal Amount of Loan N Number of monthly payments | Annual Interest Rate i Monthly Interest Rate Test Case 399.25 17,000 48 6% (1/12)/100 Monthly Payment Amount P given A, N, and I iA Number of Payments N given P, A, and I: log(1- iA P) log(1+i) Principal Loan Amount A given P, N, and I: Interest Rate I given P, A, and N (Iterative Method There is no closed form interest rate formula. Instead, the Newton iterative method is used on a modified form of the basic loan equation. This method works by inserting an initial guess for the interest rate (1-10%), then looking at the difference between the calculated (inew), and the guessed interest (1)