Derivative of \( \displaystyle \left(4 x + 2\right) e^{8 x + 4} \)
Problem 2.381 · medium
Differentiate \( \displaystyle f(x) = \left(4 x + 2\right) e^{8 x + 4} \).
- \[ \frac{d}{d x} \left(4 x + 2\right) e^{8 x + 4} \]Start with the derivative of the function.✓ Proved
- \[ = \left(4 x + 2\right) \frac{d}{d x} e^{8 x + 4} + e^{8 x + 4} \frac{d}{d x} \left(4 x + 2\right) \]productApply the product rule.✓ Proved
- \[ = \left(4 x + 2\right) \frac{d}{d x} e^{8 x + 4} + 4 e^{8 x + 4} \]derivativeDifferentiate the first part of the product.✓ Proved
- \[ = \left(4 x + 2\right) e^{8 x + 4} \frac{d}{d x} \left(8 x + 4\right) + 4 e^{8 x + 4} \]chainApply the chain rule to the exponential term.✓ Proved
- \[ = 8 \left(4 x + 2\right) e^{8 x + 4} + 4 e^{8 x + 4} \]derivativeDifferentiate the inner function 8*x + 4.✓ Proved
- \[ = \left(32 x + 16\right) e^{8 x + 4} + 4 e^{8 x + 4} \]algebraDistribute the 8 into the parentheses.✓ Proved
- \[ = \left(32 x + 20\right) e^{8 x + 4} \]algebra simplifyFactor out the common exponential term. Combine the constant terms.✓ Proved
Answer \( \left(32 x + 20\right) e^{8 x + 4} \)
✓ 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 |
| 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: pass 2026-09-20qwen3.6:27b-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.