Write a user-defined MATLAB function for the following math function: 3-0.47x y(x) = 0.6x³e +1.5xe -0.6x The input to the function is x and the output is y. Write the function such that x can be a vector (use element-by-element operations). (a) Use the function to calculate y(-2) and y(4). (b) Use the function to make a plot of the function y(x) for -4<x<8.