Derivative of \( \displaystyle \operatorname{atan}{\left(\left(5 x - 3\right)^{2} \right)} \)
Problem 2.326 · hard
Differentiate \( \displaystyle f(x) = \operatorname{atan}{\left(\left(5 x - 3\right)^{2} \right)} \).
- \[ \frac{d}{d x} \operatorname{atan}{\left(\left(5 x - 3\right)^{2} \right)} \]rewriteStart with the derivative of the function. Rewrite the power using the exponential and logarithm identity.✓ Proved
- \[ = \frac{\frac{d}{d x} \left(5 x - 3\right)^{2}}{\left(5 x - 3\right)^{4} + 1} \]chain algebraApply the chain rule for the arctangent function. Simplify the denominator by converting the exponential back to a power.✓ Proved
- \[ = \frac{2 \left(5 x - 3\right)^{2} \frac{d}{d x} \ln{\left(5 x - 3 \right)}}{\left(5 x - 3\right)^{4} + 1} \]chainApply the chain rule to the numerator.✓ Proved
- \[ = \frac{50 x - 30}{\left(5 x - 3\right)^{4} + 1} \]chain constant-multiple algebra simplifyDifferentiate the logarithm term using the chain rule. Simplify the constants in the numerator. Convert the exponential back to a power for simplification. Simplify the fraction by canceling the common term (5*x - 3).✓ Proved
Answer \( \frac{50 x - 30}{\left(5 x - 3\right)^{4} + 1} \)
✓ 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 undefined where (5*x - 3)**4 + 1 = 0 |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where (5*x - 3)**4 + 1 = 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where (5*x - 3)**4 + 1 = 0 log is undefined for non-positive arguments |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 log is undefined for non-positive arguments undefined where (5*x - 3)**4 + 1 = 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where (5*x - 3)**4 + 1 = 0 |
| 8 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where (5*x - 3)**4 + 1 = 0 |
| 9 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where (5*x - 3)**4 + 1 = 0 |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 0 undefined where (5*x - 3)**4 + 1 = 0 |
| answer, a second way | ✓ Proved | sympy 1.14.0 | SymPy differentiated f directly and got the stated answer |
Reviewers
gpt-oss:20b: passdeepseek-r1:70b: fail (style) — Step 1 is missing a rule label.qwen3.6:27b-mlx: pass — The solution correctly applies the chain rule and algebraic simplifications. The intermediate rewrite using logarithms is valid and handled correctly in subsequent steps.
Every verdict on record (13)
qwen3.6:27b-mlx: pass 2026-09-20 — The solution correctly applies the chain rule and algebraic simplifications. The intermediate rewrite using logarithms is valid and handled correctly in subsequent steps.gpt-oss:20b: pass 2026-09-20qwen3.6:27b-mlx: pass 2026-09-20 — The solution correctly applies the chain rule and algebraic simplifications. Each step isolates a single transformation, and the labels accurately reflect the operations performed.gpt-oss:20b: pass 2026-09-20qwen3.6:27b-mlx: pass 2026-09-19deepseek-r1:70b: fail (style) 2026-09-19 — Step 1 is missing a rule label.gpt-oss:20b: pass 2026-09-19qwen3.6:27b-mlx: pass 2026-09-19deepseek-r1:70b: fail (style) 2026-09-19 — Step 1 lacks a rule label, which is required by the contract.gpt-oss:20b: pass 2026-09-19qwen3.6:27b-mlx: pass 2026-09-18deepseek-r1:70b: pass 2026-09-18gpt-oss:20b: pass 2026-09-18
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.