Question

I don’t understand this it says let a and b be rational numbers

Answer 1

To answer this question we will use the following examples:

1) Let a=b, then:

`√(a*b)=√(a^2)=|a|.`

Since a is rational, then |a| is rational.

2) Let a=1 and b=2, then:

`√(1*2)=√(2).`

We know that √2 is an irrational number.

Therefore, if a and b are rational numbers, then:

`√(ab)`

is sometimes a rational number.

Answer: Third option.