Integral of \( \displaystyle e^{2 x + 1} \sin{\left(e^{2 x + 1} \right)} \)
Problem 4.798 · medium
Find \( \displaystyle \int e^{2 x + 1} \sin{\left(e^{2 x + 1} \right)} \, dx \). (Omit the constant of integration.)
- \[ \int e^{2 x + 1} \sin{\left(e^{2 x + 1} \right)}\, dx \]integral algebraStart with the integral of the given function. Multiply and divide by 2 to prepare for substitution.✓ Proved
- \[ = \int \frac{\sin{\left(e^{2 x + 1} \right)} \frac{d}{d x} e^{2 x + 1}}{2}\, dx \]rewriteExpress the integrand in terms of the derivative of the inner function.✓ Proved
- \[ = \int e^{2 x + 1} \sin{\left(e^{2 x + 1} \right)}\, dx \]simplify simplifyCalculate the derivative of the inner function. Simplify the expression inside the integral.✓ Proved
- \[ = - \frac{\cos{\left(e^{2 x + 1} \right)}}{2} \]antiderivativeIntegrate using the substitution u = exp(2*x + 1).✓ Proved
Answer \( - \frac{\cos{\left(e^{2 x + 1} \right)}}{2} + C \)
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. The reviewers disagree about how one step is explained; every verdict is in the receipt.
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 |
| 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 the stated antiderivative back to the integrand |
Reviewers
gpt-oss:20b: passqwen3.6:27b-mlx: fail (error) — Step 4 incorrectly labels the calculation of a derivative as 'simplify'. Step 5 is a logical error that undoes the previous work, returning to the original integral, which breaks the 'one change per step' rule and makes the subsequent jump to the answer in Step 6 unjustified.
Every verdict on record (4)
gpt-oss:20b: pass 2026-10-10qwen3.6:27b-mlx: fail (error) 2026-10-10 — Step 4 incorrectly labels the calculation of a derivative as 'simplify'. Step 5 is a logical error that undoes the previous work, returning to the original integral, which breaks the 'one change per step' rule and makes the subsequent jump to the answer in Step 6 unjustified.qwen3.6:27b-mlx: fail (error) 2026-10-10 — Steps 4 and 5 create a logical loop that undoes the preparation in Step 2, returning to the original integral without performing the substitution. Step 6 then claims to integrate using substitution, but the preceding steps did not execute the substitution (changing variables from x to u), making the transition from Step 5 to Step 6 invalid as a single step.gpt-oss:20b: pass 2026-10-10
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 2026-10-10 with SymPy 1.14.0.