 | Euclid - 1859 - 150 lapas
...OX x OX' = OY x OY', then the system of points X, X', Y, T', and Z, Z', are such that the enharmonic ratio of any four of them is equal to that of their four conjugates. Definition — Kadi pair of such points X, X', Y, Y', or Z, Z' are called conjugates ; and the system... | |
 | Euclid - 1868 - 138 lapas
...that OZ x UZ' — OX x OX' = OY x OY', then the system of points X, X', Y, Y', and Z, Z', are such that the anharmonic ratio of any four of them is equal to that of their four conjugates. Definition — Each pair of such points X, X', Y, Y', or Z, Z' are called conjugates ; and the system... | |
 | William John McClelland, Thomas Preston - 1893 - 402 lapas
...If A, B, C, D be these points of section, both ratios are equal to sin BO sin AD sin AB sin CD' 112 that the anharmonic ratio of any four of them is equal...Sf to the focus / is called a Double Ray, or Focal Ha'j. It obviously meets the great circle in a point F, which is its own conjugate, which is therefore... | |
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A'; B, B\ &c., in which this pencil meets the great circle, are such * If A, B, C, D be these points of section, both ratios are equal to sin 7} C sin AI) sin AB sin CD... 