State whether the following statements are true or false. Justify your answers.
$(i)$ Every irrational number is a real number.
$(ii)$ Every point on the number line is of the form $\sqrt m$ , where $m$ is a natural number.
$(iii)$ Every real number is an irrational number.
$(i)$ True ; since the collection of real numbers is made up of rational and irrational numbers.
$(ii)$ False ; as negative numbers cannot be expressed as the square root of any other number.
$(iii)$ False ; as real numbers include both rational and irrational numbers. Therefore, every real number cannot be an irrational number.
Show how $\sqrt 5$ can be represented on the number line.
Represent $ \sqrt{9.3}$ on the number line.
Classify the following numbers as rational or irrational :
$(i)$ $2-\sqrt{5}$
$(ii)$ $(3+\sqrt{23})-\sqrt{23}$
$(iii)$ $\frac{2 \sqrt{7}}{7 \sqrt{7}}$
$(iv)$ $\frac{1}{\sqrt{2}}$
$(v)$ $2 \pi$
Write the following in decimal form and say what kind of decimal expansion each has :
$(i)$ $\frac{36}{100}$
$(ii)$ $\frac{1}{11}$
$(iii)$ $4 \frac{1}{8}$
$(iv)$ $\frac{3}{13}$
$(v)$ $\frac{2}{11}$
$(vi)$ $\frac{329}{400}$
Rationalise the denominator of $\frac{1}{\sqrt{2}}$.