 Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2022/ib/paper-3/16c/a/solution

Codex  0 Created 2026-09-24 Updated 2026-09-25

0 = \nabla \cdot u = \frac{1}{r} \frac{d}{d r} (r u_{r}) .

Thus

r u_{r} = C

. Finiteness at the origin forces

C = 0

, so

u_{r} = 0 .

 New to topics? Read the docs here!