Question

which one of the following is an irrational number : a.√4 , b.3√8 , c.√100 , d.-√0.64.
I want the full explanation with answer​

Answer 1

Given:

a.√4 , b.3√8 , c.√100 , d.-√0.64.

To find:

which one of the following is an irrational number : a.√4 , b.3√8 , c.√100 , d.-√0.64.

Solution:

From given, we have,

a. √4

= √ (2 × 2)

= 2

As 2 can be expressed as a fraction 2/1, the number √4 is a rational number.

b. 3√8

= 3 √ (2 × 2 × 2)

= 3 × 2 √ (2)

= 6 √2

As 6 √2 cannot be expressed as a fraction, the number 3√8 is an irrational number.

c.√100

= √ (10 × 10)

= 10

As 10 can be expressed as a fraction 10/1, the number √100 is a rational number.

d.-√0.64.

= - √ (0.8 × 0.8)

= - 0.8

As - 0.8 can be expressed as a fraction -8/10, the number -√0.64 is a rational number.

Answer 2

Answer:

3√8

Step-by-step explanation:

3√8abolzhb hzhs stwip do dh pink jodi fund stood