3(a),(b): p. 52 of the Matlab supplement explains how to do
the Euler method in Matlab. Modify this for the improved Euler method. This
gives you a column vector t with the t-values and a
column vector y with the y-values of the improved Euler
method. The instructions for first order
ODEs explain how to obtain how to obtain a column vector yval
with the y-values of the exact solution. The table with the three
columns can then be obtained by [t,y,abs(y-yval)] .
4(b): Plot the symbolic solutions.
4(c): Select a fairly small y-range, as in (b).