Question

Proof 2 root 5 is an irrational no

Answer 1

2
$2 \sqrt{5}$
because it can't be written in the form of p by q formula

Answer 2

Let if Possible Suppose 2Root5 is a rational number
Now,
=> As 2Root5 is a rational
=> ( 2Root5 ) / 2 is also a rational number ( Rational / Rational = Rational )
=> 2 x Root5 / 2 is a rational
=> Root5 is a rational
This contradicts the fact that Root5 is an irrational number.
Hence Our assumption was wrong , Thus 2Root5 is an irrational number....