<p>Which of the followings is an irrational number?</p>
<p style="display:inline"><span class="math-tex">\((\sqrt{2}-1)^2\)</span></p>
<p style="display:inline"><span class="math-tex">\(\left(2 \sqrt{3}-\frac{1}{\sqrt{3}}\right)^2\)</span></p>
<p style="display:inline"><span class="math-tex">\(\sqrt{2}-(2+\sqrt{2})\)</span></p>
<p style="display:inline"><span class="math-tex">\(\frac{(\sqrt{2}+5 \sqrt{2})}{\sqrt{2}}\)</span></p>
Step-by-Step Solution
Key Concept: Simplify the radical expression using algebraic identities to determine if the expanded form contains any irreducible square roots.
<p><span class="math-tex">\((\sqrt{2}-1)^2\)</span></p>
Correct Answer: A