Derivative of \( \displaystyle \frac{\left(3 \sin{\left(4 x \right)} - 3 \cos{\left(4 x \right)}\right) e^{4 x}}{8} \)
Problem 2.1435 · hard
Differentiate \( \displaystyle f(x) = \frac{3 \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) e^{4 x}}{8} \).
- \[ \frac{d}{d x} \frac{\left(3 \sin{\left(4 x \right)} - 3 \cos{\left(4 x \right)}\right) e^{4 x}}{8} \]derivativeStart with the derivative of the function.✓ Proved
- \[ = \frac{3 \frac{d}{d x} \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) e^{4 x}}{8} \]constant-multiplePull out the constant factor.✓ Proved
- \[ = \frac{3 \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) \frac{d}{d x} e^{4 x}}{8} + \frac{3 e^{4 x} \frac{d}{d x} \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right)}{8} \]productApply the product rule.✓ Proved
- \[ = \frac{3 \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) e^{4 x}}{2} + \frac{3 \left(4 \sin{\left(4 x \right)} + 4 \cos{\left(4 x \right)}\right) e^{4 x}}{8} \]derivative algebraDifferentiate the trigonometric and exponential terms. Simplify the signs inside the first term.✓ Proved
- \[ = 3 e^{4 x} \sin{\left(4 x \right)} \]algebra simplify algebra simplifyFactor out 4*exp(4*x) from both terms. Combine like terms inside the parentheses. Multiply the constants. Final simplified expression.✓ Proved
Answer \( 3 e^{4 x} \sin{\left(4 x \right)} \)
✓ 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 |
| 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)
qwen3.6:27b-mlx: pass 2026-10-03gpt-oss:20b: pass 2026-10-03qwen3.6:27b-mlx: pass 2026-10-03 — The solution correctly applies differentiation rules and algebraic simplifications in a step-by-step manner. Each step changes only one aspect of the expression and uses appropriate labels from the fixed vocabulary.gpt-oss:20b: pass 2026-10-03
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 2026-10-03 with SymPy 1.14.0.