void drukujF(double a, double b, double c) 
{
	cout << "f( x )=";
	//ax^2
	if (a == -1)
	{
		cout << "-x^2";
	}
	else if (a == 1)
		cout << "x^2";
	else if (a != 0)
		cout << a << "x^2";
	//bx
	if (b > 0)
	{
		if (a != 0)
			cout << "+";
		if (b != 1)
			cout << b;
		cout << "x";
	}
	else if (b < 0)
	{
		if (b != -1)
			cout << b;
		else
			cout << "-";
		cout << "x";
	}
	//c	
	if (c > 0)
	{
		if (a != 0 || b != 0)
			cout << "+";
		cout << c;
	}
	else if (c < 0)
		cout << c;
	else if (a == 0 && b == 0)
		cout << 0;
	cout << endl;
}