∫Calc Practice

Derivative of \( \displaystyle - 3 x + \left(3 x - \frac{3}{2}\right) \ln{\left(2 x - 1 \right)} \)

Problem 2.1762 · hard

Differentiate \( \displaystyle f(x) = - 3 x + \left(3 x - \frac{3}{2}\right) \ln{\left(2 x - 1 \right)} \).
  1. \[ \frac{d}{d x} \left(- 3 x + \left(3 x - \frac{3}{2}\right) \ln{\left(2 x - 1 \right)}\right) \]
    derivativeStart with the derivative of the function.✓ Proved
  2. \[ = \frac{d}{d x} \left(- 3 x\right) + \frac{d}{d x} \left(3 x - \frac{3}{2}\right) \ln{\left(2 x - 1 \right)} \]
    sumApply the sum rule.✓ Proved
  3. \[ = \left(3 x - \frac{3}{2}\right) \frac{d}{d x} \ln{\left(2 x - 1 \right)} + \ln{\left(2 x - 1 \right)} \frac{d}{d x} \left(3 x - \frac{3}{2}\right) + \frac{d}{d x} \left(- 3 x\right) \]
    productApply the product rule.✓ Proved
  4. \[ = \left(3 x - \frac{3}{2}\right) \frac{d}{d x} \ln{\left(2 x - 1 \right)} - \ln{\left(2 x - 1 \right)} \frac{d}{d x} \frac{3}{2} + \ln{\left(2 x - 1 \right)} \frac{d}{d x} 3 x + \frac{d}{d x} \left(- 3 x\right) \]
    sumDistribute the derivative over the subtraction.✓ Proved
  5. \[ = \left(3 x - \frac{3}{2}\right) \frac{d}{d x} \ln{\left(2 x - 1 \right)} - \ln{\left(2 x - 1 \right)} \frac{d}{d x} \frac{3}{2} + 3 \ln{\left(2 x - 1 \right)} + \frac{d}{d x} \left(- 3 x\right) \]
    constantDifferentiate the constant term 3/2.✓ Proved
  6. \[ = \left(3 x - \frac{3}{2}\right) \frac{d}{d x} \ln{\left(2 x - 1 \right)} + 3 \ln{\left(2 x - 1 \right)} + \frac{d}{d x} \left(- 3 x\right) \]
    constant algebraThe derivative of a constant is zero. Simplify the expression.✓ Proved
  7. \[ = 3 \ln{\left(2 x - 1 \right)} + \frac{d}{d x} \left(- 3 x\right) + \frac{\left(3 x - \frac{3}{2}\right) \frac{d}{d x} \left(2 x - 1\right)}{2 x - 1} \]
    chainApply the chain rule to the logarithm.✓ Proved
  8. \[ = 3 \ln{\left(2 x - 1 \right)} + \frac{d}{d x} \left(- 3 x\right) + \frac{2 \left(3 x - \frac{3}{2}\right)}{2 x - 1} \]
    derivative algebraDifferentiate the inner function 2*x - 1. Simplify the product.✓ Proved
  9. \[ = 3 \ln{\left(2 x - 1 \right)} - 3 + \frac{2 \left(3 x - \frac{3}{2}\right)}{2 x - 1} \]
    derivativeDifferentiate the first term.✓ Proved
  10. \[ = 3 \ln{\left(2 x - 1 \right)} - 3 + \frac{6 x - 3}{2 x - 1} \]
    algebra algebraMultiply the numerator. Factor out 3 from the numerator.✓ Proved
  11. \[ = 3 \ln{\left(2 x - 1 \right)} \]
    simplify algebraCancel the common factor (2*x - 1). Combine the remaining terms.✓ Proved
Answer \( 3 \ln{\left(2 x - 1 \right)} \)

✓ 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
3✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
4✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
5✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
6✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
7✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
8✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where 2*x - 1 = 0
9✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where 2*x - 1 = 0
10✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where 2*x - 1 = 0
11✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where 2*x - 1 = 0
12✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where 2*x - 1 = 0
13✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where 2*x - 1 = 0
14✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
undefined where 2*x - 1 = 0
15✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
log is undefined for non-positive arguments
answer✓ Provedsympy 1.14.0final line against the stated answer: simplify(a - b) reduced to 0
log is undefined for non-positive arguments
answer, a second way✓ Provedsympy 1.14.0SymPy differentiated f directly and got the stated answer

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass
Every verdict on record (4)
  • gpt-oss:20b: pass 2026-10-07
  • qwen3.6:27b-mlx: pass 2026-10-07
  • gpt-oss:20b: pass 2026-10-07
  • qwen3.6:27b-mlx: pass 2026-10-07 — The solution correctly applies differentiation rules step-by-step, adhering to the one-change-per-step constraint. All labels are appropriate for the operations performed.

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 2026-10-07 with SymPy 1.14.0.