Derivative of \( \displaystyle \frac{\sin{\left(2 x - 3 \right)}}{2 x - 3} \)
Problem 2.628 · hard
Differentiate \( \displaystyle f(x) = \frac{\sin{\left(2 x - 3 \right)}}{2 x - 3} \).
- \[ \frac{d}{d x} \frac{\sin{\left(2 x - 3 \right)}}{2 x - 3} \]rewriteStart with the derivative of the function. Rewrite the denominator using a negative exponent.✓ Proved
- \[ = \sin{\left(2 x - 3 \right)} \frac{d}{d x} \frac{1}{2 x - 3} + \frac{\frac{d}{d x} \sin{\left(2 x - 3 \right)}}{2 x - 3} \]productApply the product rule.✓ Proved
- \[ = \sin{\left(2 x - 3 \right)} \frac{d}{d x} \frac{1}{2 x - 3} + \frac{2 \cos{\left(2 x - 3 \right)}}{2 x - 3} \]chainDifferentiate the first term using the chain rule.✓ Proved
- \[ = \frac{2 \cos{\left(2 x - 3 \right)}}{2 x - 3} - \frac{2 \sin{\left(2 x - 3 \right)}}{\left(2 x - 3\right)^{2}} \]chain algebraDifferentiate the second term using the chain rule. Simplify the expression by combining terms.✓ Proved
- \[ = \frac{2 \left(2 x - 3\right) \cos{\left(2 x - 3 \right)} - 2 \sin{\left(2 x - 3 \right)}}{\left(2 x - 3\right)^{2}} \]algebraCombine the terms over a common denominator.✓ Proved
- \[ = \frac{\left(4 x - 6\right) \cos{\left(2 x - 3 \right)} - 2 \sin{\left(2 x - 3 \right)}}{\left(2 x - 3\right)^{2}} \]simplifyFinal simplified form.✓ Proved
Answer \( \frac{2 \cos{\left(2 x - 3 \right)}}{2 x - 3} - \frac{2 \sin{\left(2 x - 3 \right)}}{\left(2 x - 3\right)^{2}} \)
✓ 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 undefined where 2*x - 3 = 0 |
| 3 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 3 = 0 |
| 4 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 3 = 0 |
| 5 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 3 = 0 |
| 6 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 3 = 0 |
| 7 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 3 = 0 |
| 8 | ✓ Proved | sympy 1.14.0 | simplify(a - b) reduced to 0 undefined where 2*x - 3 = 0 |
| answer | ✓ Proved | sympy 1.14.0 | final line against the stated answer: simplify(a - b) reduced to 0 undefined where 2*x - 3 = 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 — The solution correctly applies the product rule and chain rule in separate steps, adhering to the one-change-per-step constraint. The labels used are appropriate for the operations performed.
Every verdict on record (4)
qwen3.6:27b-mlx: pass 2026-09-21 — The solution correctly applies the product rule and chain rule in separate steps, adhering to the one-change-per-step constraint. The labels used are appropriate for the operations performed.gpt-oss:20b: pass 2026-09-21qwen3.6:27b-mlx: pass 2026-09-21 — The solution correctly applies the product rule and chain rule in separate steps, adhering to the one-change-per-step constraint. The labels used are from the allowed vocabulary and accurately describe the operations performed.gpt-oss:20b: pass 2026-09-21
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.