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Spiric SectionA curve with Cartesian equation
Around 150 BC, Menaechmus constructed Conic Sections by cutting a Cone by aPlane. Two hundred years later, the Greek mathematician Perseus investigated the curves obtained by cutting aTorus by a Plane which is Parallel to the line through the center of the Hole of the Torus(MacTutor).
In the Formula of the curve given above, the Torus is formed from a Circle of Radius whosecenter is rotated along a Circle of Radius . The value of gives the distance of the cutting Planefrom the center of the Torus.
When , the curve consists of two Circles of Radius whose centers are at and . If , the curve consists of one point (the origin), while if , no point lies on the curve. Theabove curves have , (3, 1, 2) (3, 0.8, 2), (3, 1, 4), (3, 1, 4.5), and (3, 0, 4.5). References
MacTutor History of Mathematics Archive. ``Spiric Sections.''http://www-groups.dcs.st-and.ac.uk/~history/Curves/Spiric.html.
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