Home›Calculus 3›Planes: distances and angles›Problem 9.884

Planes: distances and angles

Problem 9.884 · easy

Find an equation of the plane through \( \displaystyle (0, -1, 2) \) with normal vector \( \displaystyle \left\langle 3, 1, -4 \right\rangle \).

n · (r − P) = 0, i.e. ax + by + cz = n · P.
Reviewed
\[ \left(-4\right) 2 + 1 \left(-1\right) + 3 \cdot 0 = -9 \]
n · P.✓ Proved

Answer \( 3 x + y - 4 z = -9 \)

✓ Nihil obstat Lines: 1 proved, 1 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

Line	Status	Checked by	Detail
1	Reviewed	reviewers: gpt-oss:20b, qwen3.6:27b-mlx	a sentence; read, not computed
2	✓ Proved	sympy 1.14.0	simplify(lhs - rhs) reduced to 0
answer, a second way	✓ Checked independently	sympy 1.14.0 + mpmath 1.3.0	the plane holds P and its gradient is parallel to n

Reviewers

gpt-oss:20b: pass
qwen3.6:27b-mlx: pass — The solution correctly identifies the scalar equation of a plane using the normal vector and a point. The calculation of the constant term is correct.

Every verdict on record (6)

qwen3.6:27b-mlx: pass 2026-11-05 — The solution correctly identifies the scalar equation of a plane using the normal vector and a point. The calculation of the constant term is correct.
gpt-oss:20b: pass 2026-11-05
qwen3.6:27b-mlx: pass 2026-11-04 — The solution correctly identifies the plane equation formula and computes the constant term accurately. The final equation matches the stated answer.
gpt-oss:20b: pass 2026-11-04
qwen3.6:27b-mlx: pass 2026-11-04 — The solution correctly applies the point-normal form of the plane equation. The calculation of the constant term is correct, and the final equation matches the stated answer.
gpt-oss:20b: pass 2026-11-04

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/planes_distance_angle, checked 2026-11-05 with SymPy 1.14.0.