Problem 5 (15 points) Develop a Matlab function myCubicFit that calculates the coefficients ao through ag of the cubic polynomial f(z) = ao + a1z+a2z? +a3z3 that best fits given data points (z"%). The input arguments to the function must be the two vectors x and y that contain the values of the data points. The output of the function shall be a four-element vector a that contains the values of ao through az and the error of the fit E defined as the sum of the squares of the residuals. Do NOT use any Matlab build-in functions to solve the required