Derivative of \( \displaystyle \frac{3 \operatorname{asin}{\left(2 x - 1 \right)}}{2} \)
Problem 2.398 · medium
Differentiate \( \displaystyle f(x) = \frac{3 \operatorname{asin}{\left(2 x - 1 \right)}}{2} \).
- \[ \frac{d}{d x} \frac{3 \operatorname{asin}{\left(2 x - 1 \right)}}{2} \]derivativeStart with the derivative of the function.✓ Proved
- \[ = \frac{3 \frac{d}{d x} \operatorname{asin}{\left(2 x - 1 \right)}}{2} \]constant-multiplePull out the constant factor.✓ Proved
- \[ = \frac{3 \frac{d}{d x} \left(2 x - 1\right)}{2 \sqrt{1 - \left(2 x - 1\right)^{2}}} \]chainApply the chain rule to the arcsine function.✓ Proved
- \[ = \frac{3}{\sqrt{1 - \left(2 x - 1\right)^{2}}} \]derivative algebra algebraDifferentiate the inner linear function. Simplify the constant factors. Move the numerator into the square root denominator.✓ Proved
- \[ = \frac{3}{\sqrt{- 4 x^{2} + 4 x}} \]algebra simplify algebraExpand the squared binomial inside the square root. Combine like terms inside the square root. Factor out a 4 from the expression inside the square root.✓ Proved
- \[ = \frac{3}{2 \sqrt{- x^{2} + x}} \]algebraTake the square root of 4 out of the denominator.✓ Proved
- \[ = \frac{3}{2 \sqrt{x \left(1 - x\right)}} \]algebraFactor the quadratic expression inside the square root.✓ Proved
Answer \( \frac{3}{2 \sqrt{x \left(1 - x\right)}} \)
✓ 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] undefined where 1 - (2*x - 1)**2 = 0 |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 1 - (2*x - 1)**2 = 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 1 - (2*x - 1)**2 = 0 |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 1 - (2*x - 1)**2 = 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 1 - (2*x - 1)**2 = 0 undefined where -4*x**2 + 4*x = 0 |
| 8 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where -4*x**2 + 4*x = 0 |
| 9 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where -4*x**2 + 4*x = 0 |
| 10 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where -4*x**2 + 4*x = 0 undefined where -x**2 + x = 0 |
| 11 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where -x**2 + x = 0 undefined where x*(1 - x) = 0 |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 0 undefined where x*(1 - x) = 0 |
| answer, a second way | ✓ Proved | sympy 1.14.0 | SymPy differentiated f directly and got the stated answer |
Reviewers
gpt-oss:20b: passqwen3.6:27b-mlx: pass
Every verdict on record (6)
qwen3.6:27b-mlx: pass 2026-09-21gpt-oss:20b: pass 2026-09-21qwen3.6:27b-mlx: pass 2026-09-20 — The solution correctly applies the chain rule and simplifies the algebraic expression step-by-step. Each step changes only one aspect of the expression and uses valid labels from the fixed vocabulary.gpt-oss:20b: pass 2026-09-20qwen3.6:27b-mlx: pass 2026-09-20 — The solution correctly applies the chain rule and simplifies the algebraic expression step-by-step. Each step changes only one aspect of the expression and uses valid labels from the fixed vocabulary.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.