∫Calc Practice

Cylindrical and spherical coordinates

Problem 9.372 · easy

Convert the spherical point \( \displaystyle (\rho, \theta, \varphi) = \left(2, \frac{\pi}{2}, 0\right) \) to rectangular coordinates.
  1. \[ \left[\begin{matrix}0\\0\\2\end{matrix}\right] \]
    x = ρ sin φ cos θ, y = ρ sin φ sin θ, z = ρ cos φ.✓ Proved
Answer \( \left(0, 0, 2\right) \)

Every line of this solution was proved by the computer algebra system SymPy. The answer was also checked a second way, without looking at the solution. The reviewers disagree about how one step is explained; every verdict is in the receipt.

The full receipt
LineStatusChecked byDetail
1✓ Provedsympy 1.14.0simplify(lhs - rhs) reduced to 0
answer, a second way✓ Checked independentlysympy 1.14.0 + mpmath 1.3.0converted back to rectangular in floating point

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass — The solution correctly applies the standard spherical to rectangular conversion formulas for the given point, yielding the correct result.
Every verdict on record (4)
  • gpt-oss:20b: pass 2026-10-07
  • qwen3.6:27b-mlx: pass 2026-10-07 — The solution correctly applies the standard spherical to rectangular conversion formulas for the given point, yielding the correct result.
  • qwen3.6:27b-mlx: inconclusive 2026-10-07 — reviewer returned a non-object
  • gpt-oss:20b: pass 2026-10-07

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/cylindrical_spherical_coords, checked 2026-10-07 with SymPy 1.14.0.