Derivative of \( \displaystyle \frac{e^{4 x} \sin{\left(4 x \right)}}{4} - \frac{e^{4 x} \cos{\left(4 x \right)}}{4} \)
Problem 2.2170 · hard
Differentiate \( \displaystyle f(x) = \frac{e^{4 x} \sin{\left(4 x \right)}}{4} - \frac{e^{4 x} \cos{\left(4 x \right)}}{4} \).
- \[ \frac{d}{d x} \left(\frac{e^{4 x} \sin{\left(4 x \right)}}{4} - \frac{e^{4 x} \cos{\left(4 x \right)}}{4}\right) \]derivativeStart with the derivative of the function.✓ Proved
- \[ = \frac{d}{d x} \frac{e^{4 x} \sin{\left(4 x \right)}}{4} - \frac{d}{d x} \frac{e^{4 x} \cos{\left(4 x \right)}}{4} \]sumApply the sum rule.✓ Proved
- \[ = \frac{\frac{d}{d x} e^{4 x} \sin{\left(4 x \right)}}{4} - \frac{\frac{d}{d x} e^{4 x} \cos{\left(4 x \right)}}{4} \]constant-multiple algebraFactor out the constant 1/4. Factor out 1/4 from both terms.✓ Proved
- \[ = \frac{e^{4 x} \frac{d}{d x} \sin{\left(4 x \right)}}{4} - \frac{e^{4 x} \frac{d}{d x} \cos{\left(4 x \right)}}{4} + \frac{\sin{\left(4 x \right)} \frac{d}{d x} e^{4 x}}{4} - \frac{\cos{\left(4 x \right)} \frac{d}{d x} e^{4 x}}{4} \]productApply the product rule to both terms.✓ Proved
- \[ = e^{4 x} \sin{\left(4 x \right)} - e^{4 x} \cos{\left(4 x \right)} + \frac{e^{4 x} \frac{d}{d x} \sin{\left(4 x \right)}}{4} - \frac{e^{4 x} \frac{d}{d x} \cos{\left(4 x \right)}}{4} \]exponentialDifferentiate the exponential term.✓ Proved
- \[ = 2 e^{4 x} \sin{\left(4 x \right)} \]trig algebra algebra simplify simplifyDifferentiate the trigonometric terms. Distribute the terms inside the parentheses. Remove the inner parentheses. Combine like terms. Final simplification.✓ Proved
Answer \( 2 e^{4 x} \sin{\left(4 x \right)} \)
✓ 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 |
| 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
Every verdict on record (4)
gpt-oss:20b: pass 2026-10-13qwen3.6:27b-mlx: pass 2026-10-13gpt-oss:20b: fail (style) 2026-10-13 — Step 5 applies the product rule to two separate products in a single line, violating the rule‑by‑step granularity requirement.qwen3.6:27b-mlx: pass 2026-10-13 — The solution correctly applies differentiation rules step-by-step, adhering to the one-change-per-step constraint. The labels used are appropriate for the operations performed.
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 2026-10-13 with SymPy 1.14.0.