mation_facts() {
	document.getElementById("approximation_facts_button").style.display = "none";
	document.getElementById("approximation_facts_note").style.display = "none";
	show("fact_1");
	show("fact_2");
	show("fact_3");
}

function check_approximation_facts() {
	if(points_for_approximation.length == app_degree + 1)
		show("fact_1");

	if(app_degree == 0)
		show("fact_2");

	for(var i = 0; i < points_for_approximation.length; ++i) {
		for(var j = 0; j < i; ++j)
			if(Math.abs(points_for_approximation[i][