[list=1][*]The completed square form of the graph of a quadratic.[br][br][/*][*]The equation of a circle: (x– a)²+ (y– b)² =r².[br][br][/*][*]The intersection of a line and a circle or a parabola and a circle.[br][br][/*][*]The solution of linear or quadratic inequality.[br][/*][/list]