Derivative of \( \displaystyle e^{9 x^{2} + 1} \)
Problem 2.492 · hard
Differentiate \( \displaystyle f(x) = e^{9 x^{2} + 1} \).
- \[ \frac{d}{d x} e^{9 x^{2} + 1} \]derivativeStart with the derivative of the function.✓ Proved
- \[ = e^{9 x^{2} + 1} \frac{d}{d x} \left(9 x^{2} + 1\right) \]chainApply the chain rule.✓ Proved
- \[ = \left(\frac{d}{d x} 1 + \frac{d}{d x} 9 x^{2}\right) e^{9 x^{2} + 1} \]sumDifferentiate the sum inside the parentheses.✓ Proved
- \[ = 9 e^{9 x^{2} + 1} \frac{d}{d x} x^{2} \]derivativeDifferentiate each term separately.✓ Proved
- \[ = 18 x e^{9 x^{2} + 1} \]power simplifyApply the power rule to x**2. Simplify the final expression.✓ Proved
Answer \( 18 x e^{9 x^{2} + 1} \)
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 |
| 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
Every verdict on record (6)
qwen3.6:27b-mlx: pass 2026-09-21gpt-oss:20b: pass 2026-09-21qwen3.6:27b-mlx: pass 2026-09-20gpt-oss:20b: fail (error) 2026-09-20 — Step 4 applies both the constant‑multiple rule and the derivative rule at once, violating the one‑rule‑per‑step requirement. The correct labeling would be "constant‑multiple" for extracting the 9 and then a separate "derivative" step for x**2.qwen3.6:27b-mlx: pass 2026-09-20gpt-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.