| 释义 |
confocal, a. and n. Geom.|kənˈfəʊkəl|
[f. con- + focal.]
A. adj. Having the same focus or foci.
1867Thomson & Tait Nat. Phil. §494 Any two confocal homogeneous solid ellipsoids of equal masses produce equal attraction through all space external to both. 1881Maxwell Electr. & Magn. I. 215 The general equation of a confocal system. 1882Vines Sachs' Bot. 951 If the outline of the growing-point is an ellipse, the periclinals will be confocal ellipses; the anticlinals will be confocal hyperbolas.
B. n. A figure having the same focus as another.
1903Rep. Brit. Assoc. Advancem. Sci. 1902 506 A theorem which of course includes the corresponding proposition for confocals in plano. 1961C. C. T. Baker Dict. Math. 70 If two confocals intersect, one must be an ellipse and the other a hyperbola. |