MCQ
$\frac{1}{\big(3+2\sqrt{2}\big)}=?$
  • A
    $\frac{3-2\sqrt{2}}{17}$
  • B
    $\frac{\big(3-2\sqrt{2}\big)}{13}$
  • $\big(3-2\sqrt{2}\big)$
  • D
    None of these.

Answer

Correct option: C.
$\big(3-2\sqrt{2}\big)$
$\frac{1}{\big(3+2\sqrt{2}\big)}=\frac{1}{3+2\sqrt{2}}\times\frac{3-2\sqrt{2}}{3-2\sqrt{2}}$
$=\frac{3-2\sqrt{2}}{3^2-\big(2\sqrt{2}\big)^2}$
$=\frac{3-2\sqrt{2}}{9-8}$
$=\big(3-2\sqrt{2}\big)$
Hence, the correct option is $(c).$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free