Resumen de Eighty per cent correct

V.K. Srinivasan

• This note discusses the nuances that are involved in the selection of �Conic through Five Points� as a procedure for producing the graph of a standard ellipse whose equation is given in a canonical form, using computer software. The advantages and shortcomings are presented. It is hoped that this article will be useful for students and teachers. Even though the emphasis of this note is on the drawing of an ellipse by using the above method, the situation is valid for the construction of parabolas and hyperbolas. In an ellipse given by , the four obvious points are the vertices of a horizontal ellipse, which can be precisely plotted. If an incorrect choice of the fifth point is made, a 20% error occurs in graphing the above ellipse based on �Conic through Five Points� construction. This is the justification for the title of this article. Arguments leading to the possibility of constructing an infinity of ellipses passing through the same four vertices, A= ( - 4, 0),?B= (0, -3),?C= (4, 0)?and?D= (0, 3), are also given.