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Mathematics — CBSE Class 10 board question

Q1. [1]
$\left(\sqrt{3}+2\right)^2 + \left(\sqrt{3}-2\right)^2$ is a/an
  1. A positive rational number
  2. B negative rational number
  3. C positive irrational number
  4. D negative irrational number
Previously asked in CBSE board exam
2025 30/5/1 Q1
Generated by claude-sonnet-4-6 · 2026-06-15 10:30 · grounding rag
Model Answer

$(\sqrt{3}+2)^2 + (\sqrt{3}-2)^2 = (3+4\sqrt{3}+4)+(3-4\sqrt{3}+4) = 14$, which is a positive rational number.

Answer: A

Explanation

Using $(a+b)^2 + (a-b)^2 = 2(a^2+b^2)$, the irrational terms ($4\sqrt{3}$) cancel out, leaving $2(3+4)=14$. Examiners expect the calculation shown briefly to justify the choice.

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