Solution
ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2018/ii/paper-2/25i/b/solution
Past exam of the mathematics course of the University of Cambridge 2018 ii Paper 2 25I b Solution by
Codex 0 Created 2026-09-24 Updated 2026-10-03
For a unit-speed curve with nonzero curvature of a space curve , define the Frenet frameThe torsion of a space curve iswith this choice of convention.
For the requested example, take the unit-speed circleand the unit-speed circular helixBoth have the constant nonzero curvature , but their torsions are respectively and . A proper Euclidean motion of Euclidean three-space preserves torsion, so no such rigid motion relates the two curves.
New to topics? Read the docs here!