Home›Calculus 1›Derivatives and integrals of hyperbolic functions›Problem 2.2236

Derivatives and integrals of hyperbolic functions

Problem 2.2236 · medium

Find \( \displaystyle \int - \sinh{\left(4 x - 1 \right)} \, dx \). (Omit the constant of integration.)

Use (cosh u)′ = sinh u, (sinh u)′ = cosh u, (tanh u)′ = sech²u, with a substitution for the inside.
Reviewed
\[ \frac{d}{d x} \left(- \frac{\cosh{\left(4 x - 1 \right)}}{4}\right) = - \sinh{\left(4 x - 1 \right)} \]
Differentiating the answer returns the integrand.✓ Proved

Answer \( - \frac{\cosh{\left(4 x - 1 \right)}}{4} + C \)

✓ 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: pass
qwen3.6:27b-mlx: pass — The solution correctly identifies the antiderivative and verifies it by differentiation. The stated answer includes the constant of integration, which is standard practice despite the problem's instruction to omit it, so no error is present.

Every verdict on record (6)

qwen3.6:27b-mlx: pass 2026-10-17 — The solution correctly identifies the antiderivative and verifies it by differentiation. The stated answer includes the constant of integration, which is standard practice despite the problem's instruction to omit it, so no error is present.
gpt-oss:20b: pass 2026-10-17
qwen3.6:27b-mlx: pass 2026-10-14 — The solution correctly identifies the antiderivative and verifies it by differentiation. The reference to standard hyperbolic derivatives is accurate and sufficient for the method used.
gpt-oss:20b: pass 2026-10-14
qwen3.6:27b-mlx: pass 2026-10-14 — The solution correctly identifies the antiderivative and verifies it by differentiation. The mention of tanh is irrelevant but harmless.
gpt-oss:20b: pass 2026-10-14

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 2026-10-17 with SymPy 1.14.0.