|1.||resembling a circle|
|2.||(of fish scales) rounded, thin, and smooth-edged, as those of the salmon|
|3.||psychiatry See also cyclothymia (of a type of personality) characterized by exaggerated swings of mood between elation and depression|
|4.||geometry Compare trochoid the curve described by a point on the circumference of a circle as the circle rolls along a straight line|
|5.||a fish that has cycloid scales|
the curve generated by a point on the circumference of a circle that rolls along a straight line. If r is the radius of the circle and theta (theta) is the angular displacement of the circle, then the polar equations of the curve are x = r(theta - sin theta) and y = r(1 - cos theta)
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