Derivative of \( \displaystyle \frac{\sqrt{16 x^{2} + 8 x + 2}}{4} \)
Problem 2.1520 · hard
Differentiate \( \displaystyle f(x) = \frac{\sqrt{16 x^{2} + 8 x + 2}}{4} \).
- \[ \frac{d}{d x} \frac{\sqrt{16 x^{2} + 8 x + 2}}{4} \]Start with the derivative of the function.✓ Proved
- \[ = \frac{\frac{d}{d x} \sqrt{16 x^{2} + 8 x + 2}}{4} \]constant-multiple rewritePull out the constant factor 1/4. Rewrite the square root as a power.✓ Proved
- \[ = \frac{\frac{d}{d x} \left(16 x^{2} + 8 x + 2\right)}{8 \sqrt{16 x^{2} + 8 x + 2}} \]chain algebraApply the chain rule. Multiply the constants.✓ Proved
- \[ = \frac{32 x + 8}{8 \sqrt{16 x^{2} + 8 x + 2}} \]derivativeDifferentiate the polynomial inside.✓ Proved
- \[ = \frac{4 x + 1}{\sqrt{16 x^{2} + 8 x + 2}} \]algebra simplifyFactor out 8 from the polynomial. Simplify the expression.✓ Proved
Answer \( \frac{4 x + 1}{\sqrt{16 x^{2} + 8 x + 2}} \)
✓ 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 undefined where 16*x**2 + 8*x + 2 = 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 16*x**2 + 8*x + 2 = 0 |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 16*x**2 + 8*x + 2 = 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 16*x**2 + 8*x + 2 = 0 |
| 8 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 16*x**2 + 8*x + 2 = 0 |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 0 undefined where 16*x**2 + 8*x + 2 = 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 2026-10-04gpt-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.