∫Calc Practice

Derivative of \( \displaystyle \sqrt{2} \sqrt{x} \ln{\left(2 x \right)} \)

Problem 2.485 · hard

Differentiate \( \displaystyle f(x) = \sqrt{2} \sqrt{x} \ln{\left(2 x \right)} \).
  1. \[ \frac{d}{d x} \sqrt{2} \sqrt{x} \ln{\left(2 x \right)} \]
    derivativeStart with the derivative of the function.✓ Proved
  2. \[ = \sqrt{2} \frac{d}{d x} \sqrt{x} \ln{\left(2 x \right)} \]
    constant-multiplePull out the constant factor.✓ Proved
  3. \[ = \sqrt{2} \left(\sqrt{x} \frac{d}{d x} \ln{\left(2 x \right)} + \ln{\left(2 x \right)} \frac{d}{d x} \sqrt{x}\right) \]
    productApply the product rule.✓ Proved
  4. \[ = \sqrt{2} \left(\sqrt{x} \frac{d}{d x} \ln{\left(2 x \right)} + \ln{\left(2 x \right)} \frac{d}{d x} x^{0.5}\right) \]
    rewriteRewrite sqrt(x) as a power.✓ Proved
  5. \[ = \sqrt{2} \left(\frac{0.5 \ln{\left(2 x \right)}}{x^{0.5}} + \sqrt{x} \frac{d}{d x} \ln{\left(2 x \right)}\right) \]
    derivativeDifferentiate the power term.✓ Proved
  6. \[ = \sqrt{2} \left(\frac{0.5 \ln{\left(2 x \right)}}{x^{0.5}} + \frac{\frac{d}{d x} 2 x}{2 \sqrt{x}}\right) \]
    chainApply the chain rule to the logarithm.✓ Proved
  7. \[ = \sqrt{2} \left(\frac{0.5 \ln{\left(2 x \right)}}{x^{0.5}} + \frac{1}{\sqrt{x}}\right) \]
    derivative algebraDifferentiate the inner function 2x. Simplify the fraction.✓ Proved
  8. \[ = \sqrt{2} \left(\frac{0.5 \ln{\left(2 x \right)}}{x^{0.5}} + x^{-0.5}\right) \]
    algebraSimplify sqrt(x)/x to x**-0.5.✓ Proved
  9. \[ = \frac{\sqrt{2} \left(0.5 \ln{\left(2 x \right)} + 1\right)}{x^{0.5}} \]
    algebraFactor out x**-0.5.✓ Proved
  10. \[ = \sqrt{2} \left(\frac{0.5 \ln{\left(2 x \right)}}{x^{0.5}} + x^{-0.5}\right) \]
    simplifyFinal simplified form.✓ Proved
Answer \( \frac{\sqrt{2} \left(\log{\left(2 x \right)} + 2\right)}{2 \sqrt{x}} \)

✓ 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
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
11✓ 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 f directly and got the stated answer

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass
Every verdict on record (6)
  • qwen3.6:27b-mlx: pass 2026-09-21
  • gpt-oss:20b: pass 2026-09-21
  • qwen3.6:27b-mlx: pass 2026-09-20 — The solution correctly applies differentiation rules and algebraic simplifications. Each step changes only one aspect of the expression and uses valid labels from the fixed vocabulary.
  • gpt-oss:20b: pass 2026-09-20
  • qwen3.6:27b-mlx: pass 2026-09-20 — The solution correctly applies differentiation rules and algebraic simplifications in a step-by-step manner. Each step adheres to the single-rule constraint and uses valid labels from the fixed vocabulary.
  • gpt-oss:20b: fail (style) 2026-09-20 — Step 11 repeats the previous expression without any change, yet is labeled "simplify". This is a no‑op step that applies no rule and should be omitted or corrected.

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 2026-09-26 with SymPy 1.14.0.