Derivative of \( \displaystyle 5 x \left(16 x^{2} - 36 x + 27\right) \)
Problem 2.1112 · hard
Differentiate \( \displaystyle f(x) = 5 x \left(16 x^{2} - 36 x + 27\right) \).
- \[ \frac{d}{d x} 5 x \left(16 x^{2} - 36 x + 27\right) \]Start with the derivative of the function.✓ Proved
- \[ = 5 x \frac{d}{d x} \left(16 x^{2} - 36 x + 27\right) + \left(16 x^{2} - 36 x + 27\right) \frac{d}{d x} 5 x \]productApply the product rule.✓ Proved
- \[ = 80 x^{2} + 5 x \frac{d}{d x} \left(16 x^{2} - 36 x + 27\right) - 180 x + 135 \]constant-multipleApply the constant multiple rule to the first term.✓ Proved
- \[ = 80 x^{2} + 5 x \left(\frac{d}{d x} 27 - \frac{d}{d x} 36 x + \frac{d}{d x} 16 x^{2}\right) - 180 x + 135 \]sumDistribute the derivative across the sum.✓ Proved
- \[ = 80 x^{2} + 5 x \left(32 x - 36\right) - 180 x + 135 \]derivative simplifyDifferentiate each term inside the parentheses. Simplify the expression inside the parentheses.✓ Proved
- \[ = 240 x^{2} - 360 x + 135 \]algebra simplifyDistribute 5 and 5*x into the parentheses. Combine like terms.✓ Proved
Answer \( 15 \left(4 x - 3\right)^{2} \)
✓ 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 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 |
| 8 | ✓ 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 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 2026-09-28gpt-oss:20b: pass 2026-09-28qwen3.6:27b-mlx: pass 2026-09-28gpt-oss:20b: pass 2026-09-28
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 2026-09-28 with SymPy 1.14.0.