∫Calc Practice

Derivative of \( \displaystyle \sqrt{1 - \left(x - 1\right)^{2}} + \left(x - 1\right) \operatorname{asin}{\left(x - 1 \right)} \)

Problem 2.410 · hard Beautiful

Differentiate \( \displaystyle f(x) = \sqrt{1 - \left(x - 1\right)^{2}} + \left(x - 1\right) \operatorname{asin}{\left(x - 1 \right)} \).
  1. \[ \frac{d}{d x} \left(\sqrt{1 - \left(x - 1\right)^{2}} + \left(x - 1\right) \operatorname{asin}{\left(x - 1 \right)}\right) \]
    derivativeStart with the derivative of the function.✓ Proved
  2. \[ = \frac{d}{d x} \left(x - 1\right) \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} \]
    sumApply the sum rule.✓ Proved
  3. \[ = \left(x - 1\right) \frac{d}{d x} \operatorname{asin}{\left(x - 1 \right)} + \operatorname{asin}{\left(x - 1 \right)} \frac{d}{d x} \left(x - 1\right) + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} \]
    productApply the product rule to the second term.✓ Proved
  4. \[ = \left(x - 1\right) \frac{d}{d x} \operatorname{asin}{\left(x - 1 \right)} + \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} \]
    derivative constant-multipleDifferentiate (x - 1). Simplify the constant factor.✓ Proved
  5. \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} + \frac{\left(x - 1\right) \frac{d}{d x} \left(x - 1\right)}{\sqrt{1 - \left(x - 1\right)^{2}}} \]
    inverse-trigApply the derivative rule for arcsine.✓ Proved
  6. \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} \]
    derivative algebra rewriteDifferentiate (x - 1). Simplify the fraction. Rewrite the square root as a power.✓ Proved
  7. \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} + \frac{\frac{d}{d x} \left(1 - \left(x - 1\right)^{2}\right)}{2 \sqrt{1 - \left(x - 1\right)^{2}}} \]
    chainApply the chain rule.✓ Proved
  8. \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} + \frac{\frac{d}{d x} 1 - \frac{d}{d x} \left(x - 1\right)^{2}}{2 \sqrt{1 - \left(x - 1\right)^{2}}} \]
    algebraDistribute the derivative over the subtraction.✓ Proved
  9. \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} - \frac{\frac{d}{d x} \left(x - 1\right)^{2}}{2 \sqrt{1 - \left(x - 1\right)^{2}}} \]
    derivativeDifferentiate the constant 1.✓ Proved
  10. \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{2 - 2 x}{2 \sqrt{1 - \left(x - 1\right)^{2}}} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} \]
    powerApply the power rule to (x - 1)**2.✓ Proved
  11. \[ = \frac{1 - x}{\sqrt{1 - \left(x - 1\right)^{2}}} + \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} \]
    algebraSimplify the expression by multiplying terms.✓ Proved
  12. \[ = \operatorname{asin}{\left(x - 1 \right)} \]
    simplifyThe two terms involving the square root cancel each other out.✓ Proved
Answer \( \operatorname{asin}{\left(x - 1 \right)} \)

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

Reviewers

  • gpt-oss:20b: fail (style) — Step 5 incorrectly labels the simplification of 1*asin(x-1) as a "constant-multiple" rule; the correct label should be "simplify".
  • qwen3.6:27b-mlx: pass — The solution correctly applies differentiation rules step-by-step, adhering to the one-change-per-step constraint. The labels used are appropriate for the operations performed, and the final result is correct.
Every verdict on record (6)
  • qwen3.6:27b-mlx: pass 2026-09-21 — The solution correctly applies differentiation rules step-by-step, adhering to the one-change-per-step constraint. The labels used are appropriate for the operations performed, and the final result is correct.
  • gpt-oss:20b: fail (style) 2026-09-21 — Step 5 incorrectly labels the simplification of 1*asin(x-1) as a "constant-multiple" rule; the correct label should be "simplify".
  • qwen3.6:27b-mlx: pass 2026-09-20 — The solution correctly applies differentiation rules step-by-step, adhering to the one-change-per-step constraint. All labels are appropriate for the transformations performed.
  • gpt-oss:20b: fail (style) 2026-09-20 — Step 5 incorrectly labels the simplification of 1*asin(x‑1) as a constant‑multiple rule; it should be an algebraic simplification. No mathematical errors are present.
  • qwen3.6:27b-mlx: pass 2026-09-20 — 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.
  • gpt-oss:20b: pass 2026-09-20

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.