f = @(x) (1/x);
ul = 7;
ll = 1;

n = 10^4;
h = (ul - ll) / n;

result = f(ll) + f(ul);
for i = 1:n
    ordinate = ll + i*h;
    if mod(i, 3) == 0
        result = result + 2*f(ordinate);
    else
        result = result + 3*f(ordinate);
    end
end
result = (3*h)/8 * result;

disp("Result: " + result);