Integral of \( \displaystyle \frac{6 x - 4}{- 2 x + \left(2 x - 1\right)^{2} + 1} \)
Problem 4.471 · hard
Find \( \displaystyle \int \frac{6 x - 4}{- 2 x + \left(2 x - 1\right)^{2} + 1} \, dx \). (Omit the constant of integration.)
- \[ \int \frac{6 x - 4}{- 2 x + \left(2 x - 1\right)^{2} + 1}\, dx \]integralStart with the integral of the given function.✓ Proved
- \[ = \int \frac{6 x - 4}{4 x^{2} - 6 x + 2}\, dx \]algebra simplifyExpand the squared term. Combine like terms in the denominator.✓ Proved
- \[ = \int \frac{3 x - 2}{2 x^{2} - 3 x + 1}\, dx \]algebraDivide the numerator and denominator by 2.✓ Proved
- \[ = \int \frac{3 x - 2}{\left(x - 1\right) \left(2 x - 1\right)}\, dx \]algebraFactor the quadratic denominator.✓ Proved
- \[ = \int \left(\frac{1}{2 x - 1} + \frac{1}{x - 1}\right)\, dx \]partial-fractionsPerform partial fraction decomposition.✓ Proved
- \[ = \int \frac{1}{x - 1}\, dx + \int \frac{1}{2 x - 1}\, dx \]linearitySplit the integral into two parts.≈ Checked numerically
- \[ = \ln{\left(x - 1 \right)} + \frac{\ln{\left(2 x - 1 \right)}}{2} \]antiderivativeIntegrate both terms using the substitution rule.✓ Proved
Answer \( \ln{\left(x - 1 \right)} + \frac{\ln{\left(x - \frac{1}{2} \right)}}{2} + C \)
✓ Nihil obstat Lines: 7 proved, 2 checked numerically. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation.
The full receipt
| Line | Status | Checked by | Detail |
|---|---|---|---|
| 1 | ✓ Proved | sympy 1.14.0 | line 1 is the problem as stated |
| 2 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where -2*x + (2*x - 1)**2 + 1 = 0 undefined where 4*x**2 - 6*x + 2 = 0 |
| 3 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 4*x**2 - 6*x + 2 = 0 |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 4*x**2 - 6*x + 2 = 0 undefined where 2*x**2 - 3*x + 1 = 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x**2 - 3*x + 1 = 0 undefined where 2*x - 1 = 0 undefined where x - 1 = 0 |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 1 = 0 undefined where x - 1 = 0 |
| 7 | ≈ Checked numerically | sympy 1.14.0 | sympy 1.14.0: simplify left log(x - 1/2)/2 - log(2*x - 1)/2; numeric agreement only, at 24 of 24 sampled points undefined where 2*x - 1 = 0 undefined where x - 1 = 0 |
| 8 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 1 = 0 undefined where x - 1 = 0 log is undefined for non-positive arguments |
| answer | ≈ Checked numerically | sympy 1.14.0 | sympy 1.14.0: final line against the stated answer: simplify left -log(x - 1/2)/2 + log(2*x - 1)/2; numeric agreement only, at 24 of 24 sampled points log is undefined for non-positive arguments |
| answer, a second way | ✓ Proved | sympy 1.14.0 | SymPy differentiated the stated antiderivative back to the integrand |
Reviewers
gpt-oss:20b: passqwen3.6:27b-mlx: pass — The solution correctly simplifies the integrand, performs partial fraction decomposition, and integrates term-by-term. The final answer is algebraically equivalent to the stated answer (using log properties to combine terms).
Every verdict on record (4)
gpt-oss:20b: pass 2026-10-06qwen3.6:27b-mlx: pass 2026-10-06 — The solution correctly simplifies the integrand, performs partial fraction decomposition, and integrates term-by-term. The final answer is algebraically equivalent to the stated answer (using log properties to combine terms).gpt-oss:20b: pass 2026-10-06qwen3.6:27b-mlx: pass 2026-10-06 — The solution correctly simplifies the integrand, performs partial fraction decomposition, and integrates term-by-term. The final answer is algebraically equivalent to the stated answer (using log properties to combine terms), and all steps adhere to the single-rule constraint.
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
gemma4:26b, checked 2026-10-06 with SymPy 1.14.0.