∫Calc Practice

Derivative of \( \displaystyle e^{\cos{\left(2 x \right)}} \)

Problem 2.524 · hard

Differentiate \( \displaystyle f(x) = e^{\cos{\left(2 x \right)}} \).
  1. \[ \frac{d}{d x} e^{\cos{\left(2 x \right)}} \]
    derivativeStart with the derivative of the function.✓ Proved
  2. \[ = e^{\cos{\left(2 x \right)}} \frac{d}{d x} \cos{\left(2 x \right)} \]
    chainApply the chain rule to the exponential function.✓ Proved
  3. \[ = - e^{\cos{\left(2 x \right)}} \sin{\left(2 x \right)} \frac{d}{d x} 2 x \]
    trigDifferentiate the cosine function.✓ Proved
  4. \[ = - 2 e^{\cos{\left(2 x \right)}} \sin{\left(2 x \right)} \]
    derivative simplifyDifferentiate the inner linear function. Simplify the final expression.✓ Proved
Answer \( - 2 e^{\cos{\left(2 x \right)}} \sin{\left(2 x \right)} \)

✓ 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
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 (6)
  • qwen3.6:27b-mlx: pass 2026-09-21
  • gpt-oss:20b: pass 2026-09-21
  • qwen3.6:27b-mlx: pass 2026-09-20
  • gpt-oss:20b: pass 2026-09-20
  • qwen3.6:27b-mlx: pass 2026-09-20
  • gpt-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.