Derivative of \( \displaystyle \left(2 x - 1\right)^{2} e^{1 - 2 x} \)
Problem 2.612 · hard
Differentiate \( \displaystyle f(x) = \left(2 x - 1\right)^{2} e^{1 - 2 x} \).
- \[ \frac{d}{d x} \left(2 x - 1\right)^{2} e^{1 - 2 x} \]Start with the derivative of the function.✓ Proved
- \[ = \left(2 x - 1\right)^{2} \frac{d}{d x} e^{1 - 2 x} + e^{1 - 2 x} \frac{d}{d x} \left(2 x - 1\right)^{2} \]productApply the product rule.✓ Proved
- \[ = \left(2 x - 1\right)^{2} \frac{d}{d x} e^{1 - 2 x} + \left(4 x - 2\right) e^{1 - 2 x} \frac{d}{d x} \left(2 x - 1\right) \]powerDifferentiate the first part using the power rule.✓ Proved
- \[ = \left(2 x - 1\right)^{2} \frac{d}{d x} e^{1 - 2 x} + \left(8 x - 4\right) e^{1 - 2 x} \]derivative algebraDifferentiate the inner part of the power term. Simplify the first term.✓ Proved
- \[ = \left(2 x - 1\right)^{2} e^{1 - 2 x} \frac{d}{d x} \left(1 - 2 x\right) + \left(8 x - 4\right) e^{1 - 2 x} \]chainApply the chain rule to the exponential term.✓ Proved
- \[ = - 2 \left(2 x - 1\right)^{2} e^{1 - 2 x} + \left(8 x - 4\right) e^{1 - 2 x} \]derivative algebraDifferentiate the exponent. Simplify the expression.✓ Proved
- \[ = \left(6 - 4 x\right) \left(2 x - 1\right) e^{1 - 2 x} \]algebra algebra simplifyFactor out common terms. Distribute the -2 inside the parentheses. Combine like terms.✓ Proved
Answer \( \left(- 8 x^{2} + 16 x - 6\right) e^{1 - 2 x} \)
✓ 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
| 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 |
| 3 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 8 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 9 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 10 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 11 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 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 — The solution correctly applies the product, power, chain, and derivative rules in a logical sequence. Each step changes only one aspect of the expression, and the labels accurately reflect the operations performed.
Every verdict on record (4)
qwen3.6:27b-mlx: pass 2026-09-21 — The solution correctly applies the product, power, chain, and derivative rules in a logical sequence. Each step changes only one aspect of the expression, and the labels accurately reflect the operations performed.gpt-oss:20b: pass 2026-09-21qwen3.6:27b-mlx: pass 2026-09-21 — The solution correctly applies the product, power, chain, and derivative rules in a logical sequence. Each step isolates a single transformation, and the labels accurately reflect the operations performed.gpt-oss:20b: pass 2026-09-21
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.