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 \( \displaystyle f(x) = \sqrt{1 - \left(x - 1\right)^{2}} + \left(x - 1\right) \operatorname{asin}{\left(x - 1 \right)} \).
- \[ \frac{d}{d x} \left(\sqrt{1 - \left(x - 1\right)^{2}} + \left(x - 1\right) \operatorname{asin}{\left(x - 1 \right)}\right) \]derivativeStart with the derivative of the function.✓ Proved
- \[ = \frac{d}{d x} \left(x - 1\right) \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} \]sumApply the sum rule.✓ Proved
- \[ = \left(x - 1\right) \frac{d}{d x} \operatorname{asin}{\left(x - 1 \right)} + \operatorname{asin}{\left(x - 1 \right)} \frac{d}{d x} \left(x - 1\right) + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} \]productApply the product rule to the second term.✓ Proved
- \[ = \left(x - 1\right) \frac{d}{d x} \operatorname{asin}{\left(x - 1 \right)} + \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} \]derivative constant-multipleDifferentiate (x - 1). Simplify the constant factor.✓ Proved
- \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} + \frac{\left(x - 1\right) \frac{d}{d x} \left(x - 1\right)}{\sqrt{1 - \left(x - 1\right)^{2}}} \]inverse-trigApply the derivative rule for arcsine.✓ Proved
- \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{d}{d x} \sqrt{1 - \left(x - 1\right)^{2}} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} \]derivative algebra rewriteDifferentiate (x - 1). Simplify the fraction. Rewrite the square root as a power.✓ Proved
- \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} + \frac{\frac{d}{d x} \left(1 - \left(x - 1\right)^{2}\right)}{2 \sqrt{1 - \left(x - 1\right)^{2}}} \]chainApply the chain rule.✓ Proved
- \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} + \frac{\frac{d}{d x} 1 - \frac{d}{d x} \left(x - 1\right)^{2}}{2 \sqrt{1 - \left(x - 1\right)^{2}}} \]algebraDistribute the derivative over the subtraction.✓ Proved
- \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} - \frac{\frac{d}{d x} \left(x - 1\right)^{2}}{2 \sqrt{1 - \left(x - 1\right)^{2}}} \]derivativeDifferentiate the constant 1.✓ Proved
- \[ = \operatorname{asin}{\left(x - 1 \right)} + \frac{2 - 2 x}{2 \sqrt{1 - \left(x - 1\right)^{2}}} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} \]powerApply the power rule to (x - 1)**2.✓ Proved
- \[ = \frac{1 - x}{\sqrt{1 - \left(x - 1\right)^{2}}} + \operatorname{asin}{\left(x - 1 \right)} + \frac{x - 1}{\sqrt{1 - \left(x - 1\right)^{2}}} \]algebraSimplify the expression by multiplying terms.✓ Proved
- \[ = \operatorname{asin}{\left(x - 1 \right)} \]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
| 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 asin is real only on [-1, 1] |
| 3 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 8 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 9 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 10 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 11 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 12 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 13 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 14 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| 15 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 asin is real only on [-1, 1] undefined where 1 - (x - 1)**2 = 0 |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 0 asin is real only on [-1, 1] |
| answer, a second way | ✓ Proved | sympy 1.14.0 | SymPy 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.