from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of a family of curves defined as the locus of a point, P, on a line from a given fixed point and intersecting two given curves, C1 and C2, where the distance along the line from C1 to P remains constant and equat to the distance from P to C2.
from the GNU version of the Collaborative International Dictionary of English
- n. A curve invented by Diocles, for the purpose of solving two celebrated problems of the higher geometry; viz., to trisect a plane angle, and to construct two geometrical means between two given straight lines.
from The Century Dictionary and Cyclopedia
- n. A curve of the third order and third class, having a cusp at the origin and a point of inflection at infinity.
- n. It was invented by one Diocles, a geometer of the second century b. c., with a view to the solution of the famous problem of the duplication of the cube, or the insertion of two mean proportionals between two given straight lines. Its equation is x=y (a—x). In the cissoid of Diocles the generating curve is a circle; a point A is assumed on this circle, and a tangent M M' through the opposite extremity of the diameter drawn from A; then the property of the curve is that if from A any oblique line be drawn to M M', the segment of this line between the circle and its tangent is equal to the segment between A and the cissoid. But the name has sometimes been given in later times to all curves described in a similar manner, where the generating curve is not a circle.
- Included between the concave sides of two intersecting curves: as, a cissoid angle.
Diocles (about the end of the second century B. C.) is known as the discoverer of the _cissoid_ which was used for duplicating the cube.
The Legacy of Greece Essays By: Gilbert Murray, W. R. Inge, J. Burnet, Sir T. L. Heath, D'arcy W. Thompson, Charles Singer, R. W. Livingston, A. Toynbee, A. E. Zimmern, Percy Gardner, Sir Reginald Blomfield
I was so fascinated by the shape and mathematical description of a simple curve (cardioid or cissoid per - haps) that I had stumbled across in my reading that again I could not rest until I had explored in depth as many curves as I could