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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 \( \displaystyle f(x) = \frac{3 \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) e^{4 x}}{8} \).
  1. \[ \frac{d}{d x} \frac{\left(3 \sin{\left(4 x \right)} - 3 \cos{\left(4 x \right)}\right) e^{4 x}}{8} \]
    derivativeStart with the derivative of the function.✓ Proved
  2. \[ = \frac{3 \frac{d}{d x} \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) e^{4 x}}{8} \]
    constant-multiplePull out the constant factor.✓ Proved
  3. \[ = \frac{3 \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) \frac{d}{d x} e^{4 x}}{8} + \frac{3 e^{4 x} \frac{d}{d x} \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right)}{8} \]
    productApply the product rule.✓ Proved
  4. \[ = \frac{3 \left(\sin{\left(4 x \right)} - \cos{\left(4 x \right)}\right) e^{4 x}}{2} + \frac{3 \left(4 \sin{\left(4 x \right)} + 4 \cos{\left(4 x \right)}\right) e^{4 x}}{8} \]
    derivative algebraDifferentiate the trigonometric and exponential terms. Simplify the signs inside the first term.✓ Proved
  5. \[ = 3 e^{4 x} \sin{\left(4 x \right)} \]
    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
LineStatusChecked byDetail
1✓ Provedsympy 1.14.0line 1 is the problem as stated
2✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
3✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
4✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
5✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
6✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
7✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
8✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
9✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
answer✓ Provedsympy 1.14.0final line against the stated answer: simplify(a - b) reduced to 0
answer, a second way✓ Provedsympy 1.14.0SymPy differentiated f directly and got the stated answer

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass
Every verdict on record (4)
  • qwen3.6:27b-mlx: pass 2026-10-03
  • gpt-oss:20b: pass 2026-10-03
  • qwen3.6:27b-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.