Focal surface
For a surface in three dimension the focal surface, surface of centers or evolute is formed by taking the centers of the , which are the tangential spheres whose radii are the reciprocals of one of the principal curvatures at the point of tangency. Equivalently it is the surface formed by the centers of the circles which osculate the curvature lines. If is a point of the given surface, the unit normal and the principal curvatures at , then and are the corresponding two points of the focal surface.
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Focal surface
For a surface in three dimension the focal surface, surface of centers or evolute is formed by taking the centers of the , which are the tangential spheres whose radii are the reciprocals of one of the principal curvatures at the point of tangency. Equivalently it is the surface formed by the centers of the circles which osculate the curvature lines. If is a point of the given surface, the unit normal and the principal curvatures at , then and are the corresponding two points of the focal surface.
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For a surface in three dimensi ...... o points of the focal surface.
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In der Geometrie ist eine Bren ...... lächen einer Fläche auffassen.
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For a surface in three dimensi ...... o points of the focal surface.
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In der Geometrie ist eine Bren ...... ten wichtige Spezialfälle auf:
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Brennfläche (Geometrie)
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Focal surface
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