Newcomb, Simon, 1835-1909 · New York, H. Holt and company · leaf 183
point, P. Then, while the ruler is moved round the pivot at F\let the pencil-point slide along the edge of the ruler so as to keep thet-hread lightly stretched; the pencil-point will describe an hyperhola, be-cause in every position of P we shall have FP - FP= {FP + PB) - (FP -f PD). But FP-\- PD… … 168 PLANE ANALYTIC GEOMETRY. By interchanging the fixed extremities of the ruler and thread weshall obtain a second figure equal and similar in every respect to thefirst, but turned in the opposite direction. Thus we see that the com-plete curve consists of two branches, as represented above. 150.…
Geometry, Analytic
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
