∫Calc Practice

Integrals giving inverse trig functions

Problem 4.807 · easy

Evaluate \( \displaystyle \int \frac{1}{\sqrt{25 - x^{2}}}\, dx \).
  1. This is c·∫ dx/√(a² − x²) with a = 5.
  2. \[ \frac{d}{d x} \operatorname{asin}{\left(\frac{x}{5} \right)} = \frac{1}{\sqrt{25 - x^{2}}} \]
    An antiderivative is asin(x/5); differentiate to confirm.✓ Proved
Answer \( \operatorname{asin}{\left(\frac{x}{5} \right)} + C \)

Lines: 1 proved, 1 not checked. 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
1Not checked—a sentence; read, not computed
2✓ Provedsympy 1.14.0simplify(lhs - rhs) reduced to 0
answer, a second way✓ Checked independentlysympy 1.14.0 + mpmath 1.3.0difference quotient of the answer at x = -4.0

Reviewers

  • gpt-oss:20b: fail (misleading) — Sentence 1 incorrectly introduces an extraneous constant factor "c·"; the integral is exactly ∫dx/√(25−x²) with a=5, not multiplied by a constant.
  • qwen3.6:27b-mlx: pass — The solution correctly identifies the standard integral form and verifies the result via differentiation. The logic is sound and complete.
Every verdict on record (4)
  • gpt-oss:20b: fail (misleading) 2026-10-10 — Sentence 1 incorrectly introduces an extraneous constant factor "c·"; the integral is exactly ∫dx/√(25−x²) with a=5, not multiplied by a constant.
  • qwen3.6:27b-mlx: pass 2026-10-10 — The solution correctly identifies the standard integral form and verifies the result via differentiation. The logic is sound and complete.
  • gpt-oss:20b: pass 2026-10-10
  • qwen3.6:27b-mlx: pass 2026-10-10 — The solution correctly identifies the standard integral form and verifies the result via differentiation. The steps are sound and the conclusion is correct.

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