Find the value to three places of decimals of each of the following. It is given that
$\sqrt{2}=1.414, \sqrt{3}=1.732, \sqrt{5}=2.236, \sqrt{10}=3.162 .$
(i) $\frac{2}{\sqrt{3}}$
(ii) $\frac{3}{\sqrt{10}}$
(iii) $\frac{\sqrt{5}+1}{\sqrt{2}}$
(iv) $\frac{\sqrt{10}+\sqrt{15}}{\sqrt{2}}$
(v) $\frac{2+\sqrt{3}}{3}$
(vi) $\frac{\sqrt{2}-1}{\sqrt{5}}$
Given,
$\sqrt{2}=1.414, \sqrt{3}=1.732, \sqrt{5}=2.236, \sqrt{10}=3.162$
(i) $\frac{2}{\sqrt{3}}$
Rationalizing the denominator by multiplying both numerator and denominator with
$=\frac{2 \sqrt{3}}{\sqrt{3} \times \sqrt{3}}$
$=\frac{2 \sqrt{3}}{\sqrt{3 \times 3}}$
$=\frac{2 \sqrt{3}}{3}$
$=\frac{2 \times 1.732}{3}$
$=\frac{3.464}{3}=1.154666666$
(ii) $\frac{3}{\sqrt{10}}$
Rationalizing the denominator by multiplying both numerator and denominator with $\sqrt{10}$
$=\frac{3 \sqrt{10}}{\sqrt{10} \times \sqrt{10}}$
$=\frac{3 \sqrt{10}}{\sqrt{10 \times 10}}$
$=\frac{3 \sqrt{10}}{10}$
$=\frac{9.486}{10}=0.9486$
(iii) $\frac{\sqrt{5}+1}{\sqrt{2}}$
Rationalizing the denominator by multiplying both numerator and denominator with $\sqrt{2}$
$=\frac{(\sqrt{5} \times \sqrt{2})+\sqrt{2}}{\sqrt{2} \times \sqrt{2}}$
$=\frac{\sqrt{10}+\sqrt{2}}{2}$
$=\frac{4.576}{2}=2.288$
(iv) $\frac{\sqrt{10}+\sqrt{15}}{\sqrt{2}}$
Rationalizing the denominator by multiplying both numerator and denominator with $\sqrt{2}$
$=\frac{(\sqrt{10} \times \sqrt{2})+(\sqrt{15} \times \sqrt{2})}{\sqrt{2} \times \sqrt{2}}$
$=\frac{\sqrt{20}+\sqrt{30}}{2}$
$=\frac{(\sqrt{10} \times \sqrt{2})+(\sqrt{10} \times \sqrt{3})}{2}$
$=\frac{(3.162 \times 1.414)+(3.162 \times 1.732)}{2}$
$=\frac{(4.471068)+(5.476584)}{2}$
$=\frac{9.947652}{2}$
$=4.973826$
(v) $\frac{2+\sqrt{3}}{3}$
$=\frac{2+1.732}{3}$
$=\frac{3.732}{3}$
$=1.244$
(vi) $\frac{\sqrt{2}-1}{\sqrt{5}}$
Rationalizing the denominator by multiplying both numerator and denominator with $\sqrt{5}$
$=\frac{(\sqrt{2} \times \sqrt{5})-\sqrt{5}}{\sqrt{5} \times \sqrt{5}}$
$=\frac{\sqrt{10}-\sqrt{5}}{5}$
$=\frac{3.162-2.236}{5}$
$=\frac{0.926}{5}=0.1852$