∫Calc Practice

Integrals giving inverse trig functions

Problem 4.338 · easy

Evaluate \( \displaystyle \int_{0}^{2 \sqrt{3}} \frac{3}{x^{2} + 4}\, dx \).
  1. This is c·∫ dx/(x² + a²) with a = 2.
    Reviewed
  2. \[ \frac{d}{d x} \frac{3 \operatorname{atan}{\left(\frac{x}{2} \right)}}{2} = \frac{3}{x^{2} + 4} \]
    An antiderivative is 3*atan(x/2)/2; differentiate to confirm.✓ Proved
  3. \[ \frac{\pi}{2} \]
    Evaluate between the limits.✓ Proved
Answer \( \frac{\pi}{2} \)

✓ Nihil obstat Lines: 2 proved, 1 reviewed. 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
1Reviewedreviewers: gpt-oss:20b, qwen3.6:27b-mlxa sentence; read, not computed
2✓ Provedsympy 1.14.0simplify(lhs - rhs) reduced to 0
3✓ Provedsympy 1.14.0simplify(lhs - rhs) reduced to 0
answer, a second way✓ Checked independentlysympy 1.14.0 + mpmath 1.3.0numerical quadrature

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass — The solution correctly identifies the standard integral form, verifies the antiderivative, and correctly evaluates the definite integral to match the stated answer.
Every verdict on record (4)
  • qwen3.6:27b-mlx: pass 2026-10-04 — The solution correctly identifies the standard integral form, verifies the antiderivative, and correctly evaluates the definite integral to match the stated answer.
  • gpt-oss:20b: pass 2026-10-04
  • qwen3.6:27b-mlx: pass 2026-10-04 — The solution correctly identifies the standard integral form, computes the antiderivative, and evaluates the definite integral to the correct result.
  • gpt-oss:20b: pass 2026-10-04

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/inverse_trig_integral, checked 2026-10-04 with SymPy 1.14.0.