Look at several examples of rational numbers in the form \(\frac{p}{q}\) (q ≠ 0), where p and q are integers with no common factors other than 1 and having terminating decimal representations (expansions). Can you guess what property q must satisfy?
Terminating decimal expansion will occur when denominator q of rational number \(\frac{p}{q}\) is either of 2, 4, 5, 8, 10, and so on…
\(\frac{9}{4}\) = 2.25
\(\frac{11}{8}\) = 1.375
\(\frac{27}{5}\) = 5.4
It can be observed that terminating decimal may be obtained in the situation where prime factorisation of the denominator of the given fractions has the power of 2 only or 5 only or both.
Express the following in the form \(\frac{p }{ q}\) , where p and q are integers and q ≠ 0.
(i) 0.6(ii) 0.47 (iii) 0.001.
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) \(\frac{329}{400}\)
Classify the following numbers as rational or irrational :
(i) \(\sqrt23 \)
(ii) \(\sqrt225 \)
(iii) 0.3796
(iv) 7.478478...
(v) 1.101001000100001...
(i) The kind of person the doctor is (money, possessions)
(ii) The kind of person he wants to be (appearance, ambition)
∆ABC is an isosceles triangle in which AB = AC. Side BA is produced to D such that AD = AB (see Fig. 7.34). Show that ∠ BCD is a right angle.
