Find which of the variables `x, y, z` and `u` represent irrational numbers :(i) `x^2=5` (ii) `y^2=9`(iii)`z^2=0.04`(iv) `u^2=400/4`

Options

A. z
B. y
C. x
D. u

Answer

C

Explanation

(i) Given, `" " x^(2)=5`
on taking square root both sides we get
` x= +-sqrt5 " "[" irrational number" ] `
`y^(2) =9`
sol. (ii) Given ,
on taking square root both sides, we get
` y= +-sqrt9= +- 3`
`z^(3) =0.04 " "`[ ratonal number]
(iii) Given,
on taking square root both sides, we get
` z = sqrt(0.04)=sqrt(4/100)=2/10` [ rational number]
[ ` p/q "form" , qne 0,` p and are integers ]
(iv) Given , ` " " u^(2) = 17/4`
]on taking square root both sides, we get
`u = +- sqrt(17/4) =+-sqrt17/2`
[ Irrational number because numerator is irrational ]