∫Calc Practice

Limit of \( \displaystyle 6 x + \left(2 x - 1\right)^{2} - 4 \) as \( x \to \frac{3}{2} \)

Problem 1.226 · medium

Evaluate \( \displaystyle \lim_{x \to \frac{3}{2}} 6 x + \left(2 x - 1\right)^{2} - 4 \).
  1. \[ \lim_{x \to \frac{3}{2}^+}\left(6 x + \left(2 x - 1\right)^{2} - 4\right) \]
    limit algebraEvaluate the limit of the function at x = 3/2. Rearrange the terms.✓ Proved
  2. \[ = \lim_{x \to \frac{3}{2}^+}\left(4 x^{2} + 2 x - 3\right) \]
    simplify simplifyExpand the squared binomial. Combine like terms.✓ Proved
  3. \[ = 9 \]
    limit simplify simplifySubstitute the value x = 3/2 into the expression. Evaluate the exponent. Final calculation.✓ Proved
Answer \( 9 \)

✓ 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
3✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
4✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
5✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
6✓ Provedsympy 1.14.0simplify(a - b) reduced to 0
7✓ 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.