∫Calc Practice

Integral of \( \displaystyle \frac{\ln{\left(2 x \right)}}{4 x^{2}} \)

Problem 4.930 · medium

Find \( \displaystyle \int \frac{\ln{\left(2 x \right)}}{4 x^{2}} \, dx \). (Omit the constant of integration.)
  1. \[ \int \frac{\ln{\left(2 x \right)}}{4 x^{2}}\, dx \]
    integralStart with the integral of the given function.✓ Proved
  2. \[ = \int \frac{\ln{\left(x \right)} + \ln{\left(2 \right)}}{4 x^{2}}\, dx \]
    rewriteUse the logarithm property log(ab) = log(a) + log(b).✓ Proved
  3. \[ = \int \frac{\ln{\left(2 \right)}}{4 x^{2}}\, dx + \int \frac{\ln{\left(x \right)}}{4 x^{2}}\, dx \]
    linearitySplit the integral into two parts.✓ Proved
  4. \[ = \frac{\ln{\left(2 \right)} \int \frac{1}{x^{2}}\, dx}{4} + \int \frac{\ln{\left(x \right)}}{4 x^{2}}\, dx \]
    linearityFactor out the constants.✓ Proved
  5. \[ = \int \frac{\ln{\left(x \right)}}{4 x^{2}}\, dx - \frac{\ln{\left(2 \right)}}{4 x} \]
    antiderivativeIntegrate the first term.✓ Proved
  6. \[ = - \int \left(- \frac{1}{4 x^{2}}\right)\, dx - \frac{\ln{\left(x \right)}}{4 x} - \frac{\ln{\left(2 \right)}}{4 x} \]
    parts substitutionUse integration by parts on the second integral with u = log(x) and dv = x**(-2)/4 dx. Apply the derivative of log(x).✓ Proved
  7. \[ = \int \frac{1}{4 x^{2}}\, dx - \frac{\ln{\left(x \right)}}{4 x} - \frac{\ln{\left(2 \right)}}{4 x} \]
    algebraDistribute the negative sign.✓ Proved
  8. \[ = - \frac{\ln{\left(x \right)}}{4 x} - \frac{1}{4 x} - \frac{\ln{\left(2 \right)}}{4 x} \]
    antiderivative simplifyIntegrate the remaining term. Combine all terms into a single expression.✓ Proved
Answer \( \frac{- \ln{\left(2 x \right)} - 1}{4 x} + C \)

✓ Nihil obstat Every line of this solution was proved by the computer algebra system SymPy. 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
1✓ Provedsympy 1.14.0line 1 is the problem as stated
2✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
3✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
4✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
5✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
6✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
7✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
8✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
9✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
10✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
answer✓ Provedsympy 1.14.0final line against the stated answer: simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where x = 0
answer, a second way✓ Provedsympy 1.14.0SymPy differentiated the stated antiderivative back to the integrand

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass — The solution correctly applies logarithm properties, linearity, and integration by parts. Each step isolates a single rule application, and the labels accurately reflect the operations performed.
Every verdict on record (4)
  • gpt-oss:20b: pass 2026-10-12
  • qwen3.6:27b-mlx: pass 2026-10-12 — The solution correctly applies logarithm properties, linearity, and integration by parts. Each step isolates a single rule application, and the labels accurately reflect the operations performed.
  • qwen3.6:27b-mlx: pass 2026-10-12 — The solution correctly applies logarithm properties, linearity, and integration by parts. Each step changes only one aspect of the expression and uses valid labels from the fixed vocabulary.
  • gpt-oss:20b: pass 2026-10-12

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 2026-10-12 with SymPy 1.14.0.