Revision #1140 → #2110 · back to history
addedStraight lines have zero curvature645496e09938
addedCircle curvature equals reciprocal of radius04ed54f4d16b
addedRadius of curvature is infinite at zero curvaturef0b8afeb3aee
modifiedCross product formula for space curvesa8be4f1888e9
| Field | From #1140 | To #2110 |
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| anchor.snippet | Both the curvature | Both the curvature [ 9 ] and the curvature vector can be expressed using the vector cross product and the unit tangent vector T |
| note | Not in Mathlib4. | Not in Mathlib4. Tightened anchor snippet to the full sentence so it is a stable, meaningful anchor. |
| provenance | ai | ai-moderated |
modifiedDarboux frame315e5fb2ce96
| Field | From #1140 | To #2110 |
|---|
| note | No Darboux frame in Mathlib4. | Mathlib's Darboux file is Darboux's intermediate-value theorem for derivatives, unrelated to the Darboux frame. |
addedDarboux frame relates normal/geodesic curvatures and geodesic torsionef86d0a5152f
addedSign of Gaussian curvature on standard surfaces589c5da24854
addedSign of Gaussian curvature determines local convex vs saddle shape8c05d4a65b5c
addedSoap film has zero mean curvature03c1d277ca81