∫Calc Practice

Limit of \( \displaystyle \frac{\sqrt{x + 3} - 2}{x - 1} \) as \( x \to 1 \)

Problem 1.243 · medium

Evaluate \( \displaystyle \lim_{x \to 1} \frac{\sqrt{x + 3} - 2}{x - 1} \).
  1. \[ \lim_{x \to 1^+}\left(\frac{\sqrt{x + 3} - 2}{x - 1}\right) \]
    limit algebraState the limit with the specified direction. Multiply the numerator and denominator by the conjugate.✓ Proved
  2. \[ = \lim_{x \to 1^+} \frac{1}{\sqrt{x + 3} + 2} \]
    simplify simplify cancelSimplify the numerator. Combine terms in the numerator. Cancel the common factor (x - 1).✓ Proved
  3. \[ = \lim_{x \to 1^+} \frac{1}{4} \]
    limitEvaluate the limit by substituting x = 1.✓ Proved
  4. \[ = \frac{1}{4} \]
    simplify simplifySimplify the denominator. Final result.✓ Proved
Answer \( \frac{1}{4} \)

✓ 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 x - 1 = 0
3✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where x - 1 = 0
undefined where sqrt(x + 3) + 2 = 0
4✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where sqrt(x + 3) + 2 = 0
5✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where sqrt(x + 3) + 2 = 0
6✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
undefined where sqrt(x + 3) + 2 = 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)
  • qwen3.6:27b-mlx: pass 2026-10-05
  • gpt-oss:20b: pass 2026-10-05
  • qwen3.6:27b-mlx: pass 2026-10-05
  • gpt-oss:20b: pass 2026-10-05

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 2026-10-05 with SymPy 1.14.0.