Question

Class10 Que. Show that underroot5 is an irrational number.

Answer 1

let as take  √5 is a rational number . for same contary a and b
such that √5=a/b
squaring on both side
√5-b=a
(√5)²-(b)=(a)²
5-b²=a²⇒equation one
where c is some integer
c=(5b)
squaring on both side
5c²=25b²
c=25/5
c=5
hence proved that √5 is a irrational number