h = (b-a)/n;

	s =f(a);
	s += f(b);
	s = s/2.0;

	for (var i=1; i<=n-1; i++) {
	    s += f(a+i*h);
	}
	s = s*h;

-

        h = (b-a)/n;

	s = f(a);
	s += 4.0*f(a+h);
	s += f(b));

	for (var i=2; i<=n-2; i+=2) {
	    s += 2.0*f(a + i*h);
	    s += 4.0*f(a + (i+1)*h);
	}
	s = s*h/3.0;

-