Derivatives and integrals of hyperbolic functions
Problem 2.2519 · medium
Find \( \displaystyle \int - \sinh{\left(3 x - 2 \right)} \, dx \). (Omit the constant of integration.)
- Use (cosh u)′ = sinh u, (sinh u)′ = cosh u, (tanh u)′ = sech²u, with a substitution for the inside.Reviewed
- \[ \frac{d}{d x} \left(- \frac{\cosh{\left(3 x - 2 \right)}}{3}\right) = - \sinh{\left(3 x - 2 \right)} \]Differentiating the answer returns the integrand.✓ Proved
Answer \( - \frac{\cosh{\left(3 x - 2 \right)}}{3} + C \)
✓ 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 | a central difference, with sinh and cosh computed from exponentials by mpmath |
Reviewers
gpt-oss:20b: passqwen3.6:27b-mlx: pass — The solution correctly identifies the antiderivative and verifies it via differentiation. The reference to standard hyperbolic derivatives is accurate and sufficient for the context.
Every verdict on record (6)
qwen3.6:27b-mlx: pass 2026-10-28 — The solution correctly identifies the antiderivative and verifies it via differentiation. The reference to standard hyperbolic derivatives is accurate and sufficient for the context.gpt-oss:20b: pass 2026-10-28qwen3.6:27b-mlx: pass 2026-10-27 — The solution correctly identifies the antiderivative and verifies it by differentiation. The stated answer includes the constant of integration, which is standard practice even when the problem asks to omit it (as it is implicitly understood or the user is expected to provide the functional form).gpt-oss:20b: pass 2026-10-27qwen3.6:27b-mlx: pass 2026-10-27 — The solution correctly identifies the antiderivative and verifies it by differentiation. The mention of tanh is irrelevant but harmless.gpt-oss:20b: pass 2026-10-27
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/hyperbolic_calculus, checked 2026-10-28 with SymPy 1.14.0.