Smart, Edward Howard · London : Macmillian and Co. · leaf 41
PROeJECTION. DUALITY 13 A pencil of straight lines through a point projects into apencil of straight lines through the projection of the point. The first is self-evident (Fig. 3). For the second we notice that the planes containing V andthe several rays of the pencil each pass through the join of… … Fir;. 4. Hence they form an axial pencil, the section of which bythe plane a is a flat pencil. In like manner, forms (4) and (5) of § 8 of the precedingchapter project into similar forms. To sum up, we can state generally that: To each point in a given figure corresponds ane and only onepoint in…
Geometry, Projective
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
