Am elliptic torus is a surface of revolution which is a generalization of the ring torus. It is
produced by rotating an ellipse embedded in the -plane having horizontal semi-axis
, vertical semi-axis
, and located a distance
away from the
-axis about the
-axis. It is given by the parametric
equations
|
(1)
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|
(2)
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|
(3)
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for .
This gives first fundamental form coefficients of
|
(4)
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(5)
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(6)
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second fundamental form coefficients of
|
(7)
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(8)
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(9)
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The Gaussian curvature and mean curvature are
|
(10)
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|
(11)
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By Pappus's centroid theorems, the surface area and volume are
|
(12)
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(13)
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(14)
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(15)
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where
is a complete elliptic integral
of the second kind and
|
(16)
|
is the eccentricity of the ellipse cross section.