sum = 0;%the sumn
n = 44;%the number of intervals
pi = 3.141592654;
a = 1;%lower limit
b = 3;%upper limit
I = 1.295836866;%the real integral
i=0;

for x = a:(b-a)./n:b
    f = log(x);%the function
        
    if x == a
        sum = sum + f;
    end
    
    if x == b
        sum = sum + f;
    end
    
    if x > a && x < b
        if (rem(i,2)==0)
            sum = sum + 2*f;
        else
            sum = sum + 4*f;
        end        
    end
    
    i=i+1;
    
end
S = (sum.*(b-a))./(3*n)
E = I - S
%I - S