function simpleplot(a,b,n)
% This is a simple Matlab routine to plot a function
% on the interval [a,b] using n uniformly spaced
% points.  To change the function, modify the code
% at the indicated place

%begin by defining the arrays hold the funtion information
delta = (b-a)/n;
% define the sample points. The first and last points align with a and b.
for i = 1: n+1
   x(i) = a+ delta*(i-1);
   %change the function here
   y(i)=x(i)*sin(3*x(i));
end

%Now call the built-in Matlab plotting function
plot(x,y)
graphof=strcat('Graph of f(x)');
title(graphof)
xlabel('x')