Find which of the variables x, y, z and u represent rational numbers and which irrational numbers:
(i) x2 = 5 (ii) y2 = 9
(iii) z2 = .04 (iv) (i) x2 = 5 On taking square root on both sides, we get ⇒ x = ± √5 So, x is an irrational number. (ii) y2 = 9 On taking square root on both sides, we get ⇒ y = ± 3 So, y is a rational number. (iii) z2 = .04 On taking square root on both sides, we get ⇒ z = ± 0.2 So, z is a rational number. On taking square root on both sides, we get So, u is an irrational number because √17 is irrational.