Ivan Shishkin, Pine Forest

Weekly Problem Design Contest

Contest open

Differential equations

Starts Saturday, October 17, 2026 Deadline Friday, October 23, 2026 · Paris time Prize 100 reputation points

Create an original problem whose statement or solution involves, in one way or another, one or more differential equations.

Please note: Standard exercises and variations on well-known problems should be avoided.

How entries are judged

  • Adherence to the week’s theme
  • Originality
  • Mathematical interest
  • Clarity
  • Presentation
  • Accessibility and elegance of the solution

Rules

One entry per person. You may edit your problem until Friday at 23:500, Paris time. Admins select one winner and may also award honorable mentions. Translations of the same problem count as one entry.

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Entries

1
50Résoudre dθsin⁡(θ)=dαsin⁡(α)\displaystyle\frac{\mathrm{d}\theta}{\sin(\theta)}=\frac{\mathrm{d}\alpha}{\sin(\alpha)}FRmathman

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