Consider the following differential equation describing a plug flow bioreactor: dy/dt = -Dy + mu y dz/dt = (4 - z) D - 2 mu y where D = 0.4, mu = 0.5 z/(0.1 + z), and the initial conditions are y(0) = 1 and z(0) = 4. a) Write a Matlab code to numerically solve the initial value problem over the interval [0, 2] using Euler's method with a fixed sample period, h = 0.1. b) Repeat part a) using Heun's method and the Runge-Kutta method