If a point moves in a plane in such a way that the ratio of its distances from a fixed point in plane and a fixed straight line, is always, constant, then the locus of this point is called conic. (i) Fixed point is called focus (S), fixed straight line is called directrix and constant ratio is called eccentricity (e). (ii) The straight line which is passing through focu... https://www.expertsmind.com/course-help/?p=conic-sections-98734287128