function ask005
%Function to be integrated
f=@(x)exp(x);
%lower limit
a=0;
%upper limit
b=1;
N=[10, 20, 40, 100, 200, 400, 800, 1000];
In = NaN(size(N));
%number of panels
for j = 1:length(N)
%interval size
n=N(j);
h=(b-a)/n;
%summation of first two values
s=f(a)+f(b);
%loop for the rest of the calculations
for i=1:2:n-1
s=s+4*f(a+i*h); %summation
end
for i=2:2:n-2
s=s+2*f(a+i*h); %summation
end
%evaluate integral
I=h/3*s;
In(j) = I;
end
% plot(N,In);
% or
semilogx(N,In);
end
