Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-06T04:31:05.653Z Has data issue: false hasContentIssue false

Etude Elémentaire de l’Hyperbole Equilatére et de quelques Courtes Dérivées. By J. Lemaire. Pp. iv + 172. 12 fr. 1927. (Vuibert.)

Published online by Cambridge University Press:  03 November 2016

Abstract

Image of the first page of this content. For PDF version, please use the ‘Save PDF’ preceeding this image.'
Type
Reviews
Copyright
Copyright © Mathematical Association 1927

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

* It is often said that AB and AC subtend equal angles at P : in this form the condition is too narrow, for it excludes the arc BAC of the curve, and too wide, for it admits the parts of the line BC beyond B and C. To include the whole curve some writers say that the angles subtended at P are to be equal or supplementary, but then it is necessary explicitly to remove the whole of the line BC. We may describe the locus by saying that either the angles APB, CPA are equal or the angles APB, APC are supplementary, but surely it is better to learn so emphatic a lesson in the convenience of using crosses. Perhaps the closest accurate approach to the primitive point of view is to say that the crosses (PA, PB) and (PC, PA) are congruent.