| 释义 |
▪ I. ‖ latus1 Math.|ˈleɪtəs|
[L. = side.]
Used in the following terms in Conic sections: latus rectum, a straight line drawn through the focus of a conic at right angles to the transverse diameter, the parameter; latus primarium (see quot. 1706); † latus transversum, the transverse diameter.
1702Ralphson Math. Dict. App. Conic Sections 11 In a Parabola the Rectangle of the Diameter, and Latus Rectum, is equal to the Rectangle of the Segments of the double Ordinate. 1706Phillips (ed. Kersey), Latus primarium,..a Right-line drawn thro' the Vertex, or Top of the Section, parallel to the Base of the Triangular Section of the Cone, and within it. Ibid., Latus Transversum, (in an Hyperbola) is a Right-line lying between the Vertex's of the two opposite Sections. 1734J. Ward Introd. Math. iv. i. (ed. 6) 367 The Diameter of a Circle being that Right-line which passes thro' its Centre or Focus..may..be properly call'd the Circle's Latus Rectum: And altho' it loses the Name of Diameter when the Circle degenerates into an Ellipsis, yet it retains the Name of Latus Rectum. 1859Parkinson Optics (1866) 256 A luminous point is placed at one of the foci of a semi-elliptic arc bounded by the axis major: prove that the whole illumination of the arc varies inversely as the latus rectum.
▪ II. ‖ latus2 Antiq.|ˈleɪtəs|
[Late L. = Gr. λάτος.]
A large fish inhabiting the Nile and other regions.
1598Epulario F iiij b, To dresse a Latus or shadow fish. 1706Phillips (ed. Kersey), Latus,..a huge Fish peculiar to the River Nile, which is often of Two Hundred Pounds Weight. 1753Chambers Cycl. Supp., Latus,..the name of a fish of the coracinus, or umbra kind. 1857Birch Anc. Pottery (1858) I. 90 Among fishes, the latus,..and the oxyrhyncus. |