∫Calc Practice

Equation of a plane

Problem 9.44 · medium

Find an equation of the plane through the points \( \displaystyle (0, 3, 3),\ (-3, 1, -1),\ (3, 0, -3) \).
  1. \[ \left[\begin{matrix}-3\\-2\\-4\end{matrix}\right] \]
    PQ.Reviewed
  2. \[ \left[\begin{matrix}3\\-3\\-6\end{matrix}\right] \]
    PR.Reviewed
  3. \[ \left[\begin{matrix}0\\-2\\1\end{matrix}\right] \]
    A normal vector n = PQ × PR (scaled).Reviewed
  4. \[ -3 \]
    n · P gives the constant.Reviewed
  5. The plane is -2*y + z = -3.
    Reviewed
Answer \( - 2 y + z = -3 \)

✓ Nihil obstat Lines: 5 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. How we verify

The full receipt
LineStatusChecked byDetail
1Reviewedreviewers: gpt-oss:20b, qwen3.6:27b-mlxboth sides are the same expression: the line states a value, and the working that produced it is not on the line
2Reviewedreviewers: gpt-oss:20b, qwen3.6:27b-mlxboth sides are the same expression: the line states a value, and the working that produced it is not on the line
3Reviewedreviewers: gpt-oss:20b, qwen3.6:27b-mlxboth sides are the same expression: the line states a value, and the working that produced it is not on the line
4Reviewedreviewers: gpt-oss:20b, qwen3.6:27b-mlxboth sides are the same expression: the line states a value, and the working that produced it is not on the line
5Reviewedreviewers: gpt-oss:20b, qwen3.6:27b-mlxa sentence; read, not computed
answer, a second way✓ Checked independentlysympy 1.14.0 + mpmath 1.3.0all three points satisfy the equation

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass — The solution correctly computes the normal vector and the plane equation. The intermediate steps are algebraically verified, and the final equation matches the derived normal and constant.
Every verdict on record (6)
  • qwen3.6:27b-mlx: pass 2026-09-28 — The solution correctly computes the normal vector and the plane equation. The intermediate steps are algebraically verified, and the final equation matches the derived normal and constant.
  • gpt-oss:20b: pass 2026-09-28
  • qwen3.6:27b-mlx: pass 2026-09-27 — The solution correctly computes the normal vector via cross product and determines the plane equation. The final equation is consistent with the given points.
  • gpt-oss:20b: pass 2026-09-27
  • qwen3.6:27b-mlx: pass 2026-09-26 — The solution correctly computes the normal vector via the cross product of displacement vectors and determines the plane equation. The final equation is correct.
  • gpt-oss:20b: pass 2026-09-26

Proved: SymPy reduced the difference between the two sides to zero. Checked independently: a separate method, named above, confirmed it. Checked numerically: the two sides agree at every sampled point, which is evidence, not proof. Reviewed: a model or a person read it; that is all a sentence can have. Solution by generator:structured/plane_through_points, checked 2026-10-13 with SymPy 1.14.0.