Which Joe gave his name to ‘sloppy joes’? We look at five interesting sandwiches and their lexical origins.
noun
MathematicsA plane quartic curve consisting of two separate branches either side of and asymptotic to a central straight line (the asymptote), such that if a line is drawn from a fixed point (the pole) to intersect both branches, the part of the line falling between the two branches is of constant length and is exactly bisected by the asymptote.
- ‘The conchoid has x = b as an asymptote and the area between either branch and the asymptote is infinite.’
- ‘Dürer calls the curve ‘ein muschellini’ which means a conchoid, but since it is not a true conchoid we have called it Dürer's shell curve (muschellini = conchoid = shell).’
- ‘The ruler has a fixed distance marked on it and one mark is kept on a given line while the other traces the conchoid curve.’
- ‘Nicomedes is famous for his treatise On conchoid lines which contain his discovery of the curve known as the conchoid of Nicomedes.’
- ‘Nicomedes, who was highly critical of Eratosthenes' mechanical solution, gave a construction which used the conchoid curve which he also used to solve the problem of trisection of an angle.’
- ‘Pappus tells us about the conchoid of Nicomedes in his Mathematical collection.’
Origin
Early 18th century: from conch + -oid.
Pronunciation
Further reading
6 punctuation marks you might be using incorrectly
Read moreWe take a look at several popular, though confusing, punctuation marks.
An A-Z of country name origins
Read moreFrom Afghanistan to Zimbabwe, discover surprising and intriguing language facts from around the globe.