Strictly MATLAB please.. thank you very much.

Please key answers be legible

n 2 (10+10 20 marks) Write a MATLAB function that will take as input a function f of a vector x, a lower limit xl, and an upper limit xu and return the (x,y) coordinates of both the maximum and minimum y values in the domain. The function should return an error if xl is greater than or equal to xu. The first line of the function should be: a. function [xmin, ymin, xmax, ymax]-minmax(f,xl,xu Write a script file or void function file that analyzes the range of the function f(x)- x3+ 2x+ 10. It should repeatedly prompt the user for lower and upper levels for x, plots f(x) between the between those two limits, then calculates the distance between the maximum and minimum values of f(x). The script should include a command that prints the value of this distance nicely formatted. The program should end when the user inputs a negative value for the lower value of x. You may make use of function minmax. b. 18