7. Create a function called myHWfn that will calculate y as a function of x, according to y = x3-4x2 + sin (x) Prompt the user for minimum and maximum values of x, and then: (a) Create a data file HWdata.txt containing a 20 x 2 table of x and y values from the minimum to maximum x value. (b) Create a plot of the function over the range specified (use fplot) (c) Calculate and output the integral of the function over the specified range (use integral)