Question

Prove that 2√2 is irrational after proving √2 is irrationl

Answer 1

$2 \times \sqrt{2 } = \sqrt{2 \times 4 } \\ \sqrt{8} = 2 \sqrt{2}$

Answer 2

let √2 be a rational number
so, √2 =a/b
then, a=√2b
=>a²=2b²
a devides √2b
then ,2c=a
then 4c²=2b²
then c/b=2 so √2 is irrational