Integral of \( \displaystyle 2 x + \frac{1}{2 x} \)
Problem 4.275 · medium
Find \( \displaystyle \int 2 x + \frac{1}{2 x} \, dx \). (Omit the constant of integration.)
- \[ \int \left(2 x + \frac{1}{2 x}\right)\, dx \]integralStart with the integral of the given expression.✓ Proved
- \[ = \int \frac{1}{2 x}\, dx + \int 2 x\, dx \]linearity algebraSplit the integral into two parts using linearity. Factor out the constant 1/2 from the second term.✓ Proved
- \[ = \frac{\int \frac{1}{x}\, dx}{2} + 2 \int x\, dx \]algebraFactor out the constant 2 from the first term.✓ Proved
- \[ = x^{2} + \frac{\ln{\left(x \right)}}{2} \]antiderivativeEvaluate the integrals of x and 1/x.✓ Proved
Answer \( x^{2} + \frac{\ln{\left(x \right)}}{2} + C \)
✓ 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 undefined where x = 0 |
| 3 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where x = 0 |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where x = 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where x = 0 log is undefined for non-positive arguments |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 0 log is undefined for non-positive arguments |
| 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: pass
Every verdict on record (4)
qwen3.6:27b-mlx: pass 2026-10-04gpt-oss:20b: pass 2026-10-04qwen3.6:27b-mlx: pass 2026-10-04gpt-oss:20b: pass 2026-10-04
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 2026-10-04 with SymPy 1.14.0.