Home›Calculus 3›Planes: distances and angles›Problem 9.880

Planes: distances and angles

Problem 9.880 · easy

Find the distance from \( \displaystyle (1, -1, -3) \) to the plane \( \displaystyle - 3 x + 3 y + 4 z = 0 \).

Distance = |ax₀ + by₀ + cz₀ − d| / ‖n‖.
Reviewed
\[ \frac{\left|{4 \left(-3\right) - 3 \cdot 1 + 3 \left(-1\right) + 0}\right|}{\sqrt{\left(-3\right)^{2} + 3^{2} + 4^{2}}} = \frac{9 \sqrt{34}}{17} \]
Substitute.✓ Proved

Answer \( \frac{9 \sqrt{34}}{17} \)

✓ 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 foot of the perpendicular found numerically, then the distance to it

Reviewers

gpt-oss:20b: pass
qwen3.6:27b-mlx: pass — The solution correctly applies the point-to-plane distance formula and performs the arithmetic accurately.

Every verdict on record (6)

qwen3.6:27b-mlx: pass 2026-11-05 — The solution correctly applies the point-to-plane distance formula and performs the arithmetic accurately.
gpt-oss:20b: pass 2026-11-05
qwen3.6:27b-mlx: pass 2026-11-04 — The solution correctly applies the point-to-plane distance formula with the appropriate coefficients and point coordinates.
gpt-oss:20b: pass 2026-11-04
qwen3.6:27b-mlx: pass 2026-11-04 — The solution correctly applies the point-to-plane distance formula. The substitution of coordinates and coefficients is accurate, and the final simplification is correct.
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.