∫Calc Practice

Converting between polar and rectangular coordinates

Problem 8.194 · easy

Convert the polar point \( \displaystyle \left(5, \frac{\pi}{3}\right) \) to rectangular coordinates.
  1. \[ \left[\begin{matrix}\frac{5}{2}\\\frac{5 \sqrt{3}}{2}\end{matrix}\right] \]
    x = r cos θ, y = r sin θ.✓ Proved
Answer \( \left(\frac{5}{2}, \frac{5 \sqrt{3}}{2}\right) \)

✓ Nihil obstat 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. Reviewers found nothing wrong with the explanation.

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 1.3.0floating point

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: fail (style) — The solution lacks any explanatory text or setup, presenting only a tautological matrix equality without deriving the result from the given polar coordinates.
Every verdict on record (4)
  • gpt-oss:20b: pass 2026-10-10
  • qwen3.6:27b-mlx: fail (style) 2026-10-10 — The solution lacks any explanatory text or setup, presenting only a tautological matrix equality without deriving the result from the given polar coordinates.
  • gpt-oss:20b: pass 2026-10-10
  • qwen3.6:27b-mlx: pass 2026-10-10 — The solution correctly applies the conversion formulas x = r cos θ and y = r sin θ to the given polar coordinates, resulting in the correct rectangular coordinates.

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/polar_conversion, checked 2026-10-10 with SymPy 1.14.0.