Problem 1
Begin from the exact definitions, verify all hypotheses, use X_u×X_v≠0, distinguish local from global conclusions, and test the result on a standard model and a boundary or counterexample case.
Faculty solution guide
Accept equivalent mathematically correct reasoning. Require explicit definitions, theorem hypotheses, proof structure, verification, and limitations.
Begin from the exact definitions, verify all hypotheses, use X_u×X_v≠0, distinguish local from global conclusions, and test the result on a standard model and a boundary or counterexample case.
Identify the first invalid inference, missing hypothesis, quantifier error, unjustified limit interchange, or unproved existence claim; then supply a valid repair.
A complete response explicitly states the definitions, domain, hypotheses, exact target, and theorem dependencies for Parametrized Surfaces and Tangent Planes.
The argument must address checking regular patches and computing normal fields with each nontrivial step justified and the final conclusion restated.
A strong application explains the mathematical model in computer graphics, architecture, materials, trajectories, surface reconstruction, and shape optimization, verifies conditions, and names at least one limitation.
Accept a second valid proof, a counterexample showing necessity of a hypothesis, an independent estimate, or a reproducible finite check that is correctly described as supporting evidence.