The word "epicycloid" (/ˌepɪˈsɪkloʊɪd/) is spelled phonetically according to the International Phonetic Alphabet (IPA). The first syllable "e-pi" is pronounced with a short "e" sound followed by a stressed "i" sound, represented by the IPA symbol /ɪ/. The second syllable "cy" is pronounced with a long "i" sound, represented by the IPA symbol /aɪ/. The final syllable "cloid" is pronounced with a short "o" sound followed by a soft "d" sound, represented by the IPA symbols /ɔɪd/. Together, these sounds form the word "epicycloid".
An epicycloid is a geometric curve that is formed by tracing a point on the circumference of a smaller circle that is rolling along the outside of a larger fixed circle. More specifically, it is a type of epitrochoid, which is a curve generated by tracing a point on the circumference of a smaller circle that is rolling around the inside or outside of a larger circle.
The epicycloid is characterized by its unique shape, which consists of a series of loops that are formed as the smaller circle rolls along the circumference of the larger circle. These loops are smooth and continuous, and the number of loops depends on the ratio of the radii of the two circles. If the ratio of the radii is rational, the epicycloid will be a closed curve, while if the ratio is irrational, the epicycloid will be a non-repeating curve.
Epicycloids have been studied extensively in mathematics due to their intricate and aesthetically pleasing patterns. They have applications in various fields, including physics, engineering, and computer graphics. Additionally, epicycloids have historical significance, as they were studied by ancient mathematicians such as Archimedes and were used in the design of gears for mechanical devices.
A curve described by the movement of the circumference of one circle on the convex or concave part of the circumference of another.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
The word "epicycloid" is formed from two components: "epi-" and "cycloid".
The prefix "epi-" in Greek means "upon" or "above". It is commonly used in scientific and technical terms to indicate something that is placed on or superimposed. In the case of "epicycloid", "epi-" is used to describe the geometric concept of a curve on or above a cycloid.
The term "cycloid" comes from the Greek word "kyklos", meaning "circle". A cycloid is a curve traced by a point on the circumference of a rolling circle.
So, combining the two components, "epicycloid" refers to a curve that is formed by tracing a point on or above the circumference of a rolling circle.