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Home›Calculus 1›L'Hôpital's rule›Problem 1.427

Limit of \( \displaystyle \frac{e^{6 x - 2} - 1}{\sin{\left(3 x - 1 \right)}} \) as \( x \to \frac{1}{3} \)

Problem 1.427 · medium

Evaluate \( \displaystyle \lim_{x \to \frac{1}{3}} \frac{e^{6 x - 2} - 1}{\sin{\left(3 x - 1 \right)}} \).
  1. \[ \lim_{x \to \frac{1}{3}^+}\left(\frac{e^{6 x - 2} - 1}{\sin{\left(3 x - 1 \right)}}\right) \]
    limitStart with the original limit.✓ Proved
  2. \[ = \lim_{x \to \frac{1}{3}^+}\left(\frac{\frac{d}{d x} \left(e^{6 x - 2} - 1\right)}{\frac{d}{d x} \sin{\left(3 x - 1 \right)}}\right) \]
    lhopitalThe limit is an indeterminate form 0/0, so we apply L'Hôpital's Rule.✓ Proved
  3. \[ = \lim_{x \to \frac{1}{3}^+}\left(\frac{2 e^{6 x - 2}}{\cos{\left(3 x - 1 \right)}}\right) \]
    simplify simplifyCompute the derivatives of the numerator and denominator. Simplify the fraction by dividing the constants.✓ Proved
  4. \[ = 2 \]
    limit simplify simplify simplifySubstitute the value x = 1/3 into the expression. Simplify the arguments of the exponential and trigonometric functions. Evaluate the exponential and cosine functions. Final result.✓ Proved
Answer \( 2 \)

✓ 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
LineStatusChecked byDetail
1✓ Provedsympy 1.14.0line 1 is the problem as stated
2✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where sin(3*x - 1) = 0
undefined where Derivative(sin(3*x - 1), x) = 0
3✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where Derivative(sin(3*x - 1), x) = 0
undefined where cos(3*x - 1) = 0
4✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where cos(3*x - 1) = 0
5✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where cos(3*x - 1) = 0
6✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
7✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
8✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
answer✓ Provedsympy 1.14.0final line against the stated answer: simplify(a - b) reduced to 0
answer, a second way✓ Provedsympy 1.14.0SymPy took the limit from both sides and got the stated value

Reviewers

  • gpt-oss:20b: pass
  • qwen3.6:27b-mlx: pass
Every verdict on record (4)
  • gpt-oss:20b: pass 2026-10-08
  • qwen3.6:27b-mlx: pass 2026-10-08
  • qwen3.6:27b-mlx: pass 2026-10-08 — The solution correctly applies L'Hôpital's Rule and simplifies the resulting expression step-by-step. Each step changes only one aspect of the expression and uses valid labels from the fixed vocabulary.
  • gpt-oss:20b: pass 2026-10-08

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 2026-10-08 with SymPy 1.14.0.