(a Write a MATLAB code to plot the polynomial y-0.001x4 0.051x-0.76x2 3.8x -1.4 in the domain 1 x 14.First create a vector of x with 200 terms, next use the polyval function to calculate y, and then use the plot function. (10 marks) (b) Most banks offer differential interest rates. Suppose the rate is 6% if the amount in your savings account is less than $4000, 8% for balances of $4000 or more but less than $8,000, 9% for balances of $8000 or more but less than $12,000, and 10% for balances of $12,000 or more. The following MATLAB code is for calculating your balance in a bank after one year when you received the interest. Find at least four errors in the code. For each error identified, explain why the error is caused (10 marks) ballinspace [0,1000001: if bal