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)

Question

Find which of the variables x, y, z and u represent rational numbers and which irrational numbers: (i) x 2 = 5 (ii) y 2 = 9 (iii) z 2 = .04 (iv)

Philoid · Accepted Answer

(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.

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)