Derivative of \( \displaystyle x e^{2 x} - \frac{e^{2 x}}{2} \)
Problem 2.1572 · hard
Differentiate \( \displaystyle f(x) = x e^{2 x} - \frac{e^{2 x}}{2} \).
- \[ \frac{d}{d x} \left(x e^{2 x} - \frac{e^{2 x}}{2}\right) \]Start with the derivative of the function.✓ Proved
- \[ = \frac{d}{d x} x e^{2 x} - \frac{d}{d x} \frac{e^{2 x}}{2} \]sum constantApply the sum rule. Factor out the constant 1/2.✓ Proved
- \[ = x \frac{d}{d x} e^{2 x} + e^{2 x} \frac{d}{d x} x - \frac{d}{d x} \frac{e^{2 x}}{2} \]productApply the product rule to the first term.✓ Proved
- \[ = x \frac{d}{d x} e^{2 x} + e^{2 x} - \frac{d}{d x} \frac{e^{2 x}}{2} \]derivative algebraDifferentiate x. Simplify 1*exp(2*x).✓ Proved
- \[ = 2 x e^{2 x} + e^{2 x} - \frac{d}{d x} \frac{e^{2 x}}{2} \]chain algebraDifferentiate exp(2*x) using the chain rule. Simplify x*(2*exp(2*x)).✓ Proved
- \[ = 2 x e^{2 x} \]chain algebra simplifyDifferentiate the last term using the chain rule. Simplify 1/2 * 2 * exp(2*x). Combine like terms.✓ Proved
Answer \( 2 x e^{2 x} \)
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. The reviewers disagree about how one step is explained; every verdict is in the receipt.
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: fail (error) — Step 3 is labeled 'constant' but does not factor out the constant; it merely rewrites the term. The constant factor is not pulled out until Step 9, making Step 3 an invalid application of the constant rule.
Every verdict on record (4)
qwen3.6:27b-mlx: fail (error) 2026-10-05 — Step 3 is labeled 'constant' but does not factor out the constant; it merely rewrites the term. The constant factor is not pulled out until Step 9, making Step 3 an invalid application of the constant rule.gpt-oss:20b: pass 2026-10-05qwen3.6:27b-mlx: pass 2026-10-05gpt-oss:20b: pass 2026-10-05
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 2026-10-05 with SymPy 1.14.0.