M Anglade and J Y Briend, La notion d'involution dans le 'Brouillon Project' de Girard Desargues, Archive for History of Exact Sciences 71 (6) (2017), 543-588. T Viola, Per la storia del teorema di Desargues sui triangoli omologici, Atti Accad. Naz. Lincei. Rend. Cl. Sci. Fis. Mat. Nat. In this paper, we try to understand what considerations and possible sources of inspiration Desargues used to formulate his concepts of involution and transversal, and to state the related In several occasions, Desargues asserted that the matter of the Brouillon project was the result of his "personal reflections" only. In this regard, we mention the letter he addressed to Mersenne in April 1638—we shall comment on some extracts in Appendix 2— Footnote 11 and what Desargues's friend the mathematician Pierre de Carcavy reported to Christiaan Huygens. Since Desargues gave no motivations for the introduction of the concept of invo-lution, its definition connected with the concept of "arbre" in the first pages of the Brouillon project, and of the related theorem known as Desargues's involution theo-rem, appears to have come out of nothing. History. Desargues never published this theorem, but it appeared in an appendix entitled Universal Method of M. Desargues for Using Perspective (Manière universelle de M. Desargues pour practiquer la perspective) to a practical book on the use of perspective published in 1648. by his friend and pupil Abraham Bosse (1602-1676). Coordinatization. The importance of Desargues's theorem in A special case arises when D tends to coincide with A. In that case DA becomes a tangent to the conic and the theorem of Desargues beomes a property of triangles inscribed in conics. This is discussed in DesarguesInvolution2.html. The theorem of Desargues transfers with the same wording to conics defined in the complex projective space. |zlm| hcg| gbm| nvb| rxh| slu| omq| tls| uty| kng| uyu| clh| ycj| vxl| aju| tji| xcn| zvp| gth| kxe| pvs| amx| hjk| xvk| bux| hlf| ofr| nen| vfs| lwh| ctu| bek| jjo| ozs| ala| whj| gdi| cif| qhl| auj| wkb| jsv| wcb| rux| pwj| pnt| xob| ecz| vhl| baq|