Question
If $\sqrt{2}=1.414$ then $\sqrt{\frac{\big(\sqrt{2}-1\big)}{\big(\sqrt{2}+1\big)}}=?$

Answer

  1. 0.414
    Solution:
    $\sqrt{\frac{\big(\sqrt{2}-1\big)}{\big(\sqrt{2}+1\big)}}=\sqrt{\frac{\big(\sqrt{2}-1\big)}{\big(\sqrt{2}+1\big)}\times\frac{\big(\sqrt{2}-1\big)}{\big(\sqrt{2}-1\big)}}$
    $=\sqrt{\frac{\big(\sqrt{2}-1\big)^2}{\big(\sqrt{2}\big)^2-(1)^2}}$
    $=\sqrt{\frac{\big(\sqrt{2}-1\big)^2}{1}}$
    $=\sqrt{\big(\sqrt{2}-1\big)^2}$
    $=\sqrt{2}-1$
    $=1.414-1$
    $=0.414$
    Hence, the correct option is (c).

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