Question

How to prove if a root number is irrational ? My teacher tought me condradiction method but how will it work? that way i can also prove root 16 is irrational where as it is not irrational.

Answer 1

Dear friend,

I can understand what you are trying to say... but that's how it works.

Even my teacher taught the contradiction method. But when I tried doing what u said (provin that 16 is irrational) it's not working. I have a feeling that u must have done the wrong method.

Answer 2

Proof number one: the Euclid-esque one

This is the proof given by a participant in answer to the problem I posed.

If root 5 were rational it could be written as a fraction a/b in lowest terms, i.e. in which a and b are integers and do not have a common factor other than 1. Then it would be so that