Let the conic be projected into a circle, and the quadrilateral into a parallelogram (Art. 352). ... We may project several properties relating to foci by the help of the definition of a focus given page 242, viz. that if F be a ... In this example we substitute for the word a#39; circle, a#39; aconic through two fixed points A, B, aquot; (Art. 267), and for the word a#39; centre, a#39; a pole of the line AB. ... points is a be on a fixed line. (Art . l9l.) right line. a#39; It is easy _to see, that the equation of 306 THE METHOD or PROJECTION.
|Title||:||A Treatise on Conic Sections Containing an Account of Some of the Most Important Modern Algebraic and Geometric Methods by George Salmon|