In the following equations, find which variables `x ,\ y ,\ z` etc. represent rational or irrational numbers: `x^2=5\ ` (ii) `y^2=9` (iii) `z^2=0. 04` (iii) `u^2=(17)/4`

Explanation

(i) `y^2 = 9`
On simplifying, we obtain
⇒` y = ± 3`
Therefore, y is a rational number.
(ii) `z^2 = .04`
On simplifying, we obtain
⇒ `z = ± 0.2`
Therefore, z is a rational number.
(iii) `u^2 = 17/4`
On simplifying, we obtain
⇒ `u = ±sqrt (17/2)`
`sqrt 17` is irrational.
Therefore, u is an irrational number