f = @(x) (x^2 + 5);
l1 = 5;
l2 = 7;

n = 10^4;
h = (l2 - l1) / n;

res = f(l1) + f(l2);
for o = l1 + h:h:l2 - h
    res = res + 2*f(o);
end
res = h/2 * res;

disp("Area: " + res);