Write a Matlab function to evaluate the following expression and its derivative: y(x) = (1 + r)e^x/1 + re^(1 + r) x where r can be any number greater than -1. The function call that you make on a Matlab command line or in a Matlab script should look something like: [y, dy] = func (x, r): The function should be written so that x can be a vector. Since r is a parameter, it can be treated as a scalar quantity in the function. Use your function to create plots for 0