Principles of modern geometry, with numerious applications to plane and spherical figures; and an appendix, containing questions for exercise. Intended chiefly for the use of junior students (1862)
Mulcahy, John, 1810?-1853 · Dublin Hodges, Smith · leaf 182
F, andtherefore HC • CI = BF • FA = the square of the semi-axisminor CD (since F is one of the foci). It follows, that the pointD lies on the circumference of the circle above mentioned,having HI for its diameter, and consequently lies on the surfaceof the cone. Again, it is evident that the… … 172 THE SPHERICAL ELLIPSE. their semi-axes equal and coincident, and therefore are identi-cal. This proves the theorem in the case of the ellipse. Should the curve to be projected be the parabola or hyper-bola the same method still applies; although the demonstrationabove given will require to be…
Geometry -- Problems, exercises, etc · Geometry
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
