% 0.5708

f = @(x) (x*cos(x));
ll = 0;
ul = pi/2;

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

result = f(ul) + f(ll);
for i = (ll + h):2*h:(ul - h)
    result = result + 4 * f(i);
end
for i = (ll + 2*h):2*h:(ul - h)
    result = result + 2 * f(i);
end
result = result * (h / 3);

disp("Result: " + result);