Question

Prove that 3/root 5 is irrational

Answer 1

let us assume that 3/root 5 is rational.
therefore, 3/root 5=a/b where a and b are integers 
=> /root 5 = a/3b
here, a, b and 3 are integers 
therefore a/3b is rational 
so, /root 5  is rational
but this contradicts the fact that /root 5 is irrational.
our assumtion is wrong 
therefore 3/root 5 is irrrational.