conchoid

n. 蚌线

发音

US

词形变化

conchoids 复数 conchoids

释义与例句

n.
  1. 1.

    Any of a family of curves defined as the locus of points p, such that each p is on a line that passes through a given fixed point P and intersects a given curve, C, and the distance from p to the point of intersection with C is a specified constant (note that for nontrivial cases two such points p satisfy the criteria, and the resultant curve has two parts).

    数学

    The conchoid of a circle with respect to a point on the circle is a cardioid if the fixed distance is equal to the diameter of the circle.

    The Conchoid of Nicomedes is the conchoid of a straight line with respect to a point not on the line.

    1815, Charles Hutton, Pappus, entry in A Philosophical and Mathematical Dictionary, Volume 2, page 147, He next treats of the properties of the Conchoid, which Nicomedes invented for doubling the cube; applying it to the solution of certain problems concerning Inclinations, with the finding of two mean proportionals, and cubes in any proportion whatever.

  2. 2.

    A conchoidal fracture in rock.

    地质

词汇关系

名词

上位词 1

curve

词源

From Latin concha (“mussel”) (from Ancient Greek κόγχη (kónkhē)) + -oid or directly from Ancient Greek κογχοειδής (konkhoeidḗs), referring to the curved outline of a mussel shell or anything in this form. By surface analysis, conch + -oid.

来源：wiktionary