Saturday, December 22, 2012

Irrationality

Irrationality of 2 :-

Let, the converse √ 2 = m / n is where m is Integer and n is Natural and m/n is irreducible over Integer .

Now mn2 = 2
=>  m2 = 2* n2
=> 2 | m2
=> 2 | m  [As only squire of  an even number is even in Integer ]
=> 4 | n2
=> 2 | n
=> 2 | m,n so m/n is not irreducible over Integer . (Contradicts)

Similarly to prove that p is irrational  where p is prime we will follow the same path .

Let, Irreducible over Integer m/n = √ p  where m is Integer n is Natural
=>   m2 = p * n2
=>   p | m => p | n => m/n is reducible (Contradict)

Similarly for p is prime and p1/a is irrational [ we will assume the same and ma = p . na → p | m  p | n then m/n is reducible so contradicts ]


We can further say if n = p1α1 . p2α2.. [ ∀pi are primes ] then n1/a will be irrational

if αi can s.t a  αi.

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