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is square root of 6 an irrational number?
 Sep 3, 2013
 #1
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sqrt(6) = sqrt(2*3) = sqrt(2) * sqrt(3)
2 and 3 are prime numbers. You've got two prime numbers without an even exponent. The square root of every prime number is an irrational number sqrt(6) is an irrational number.
 Sep 3, 2013
 #2
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Apfelkuchen:

sqrt(6) = sqrt(2*3) = sqrt(2) * sqrt(3)
2 and 3 are prime numbers. You've got two prime numbers without an even exponent. The square root of every prime number is an irrational number sqrt(6) is an irrational number.


actualy 6 is a whole number and whole numbers are always rational irrational numbers are not whole not a integer or natural
therefor it cant be irrational
 Sep 3, 2013
 #3
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So the square root of 2 would also be a rational number, because 2 is rational? Of course not.
6 is a rational number, thats correct.
But as we know, every square root of a number n is either an irrational number or an integer.

Claim: sqrt(6) is a rational number.
Therefore we could create an equation like sqrt(6) = n/k with n,k being integers > 1.
6 = (n/k)^2 = (n^2)/(k^2)
6*k^2 = n^2

We can see, that 6*k^2 is always even n^2 is also even n is even
So we rephrase the equation with 6*k^2 = n^2 = (2a)^2; n = 2a
(6*k^2)/2 = 2a^2 = 3*k^2

2a^2 is always even. Therefore 3*k^2 has to be even. This is only the case if k is even.
k = 2b
2a^2 = 3*k^2 = 3*(2b)^2 = 3*4b^2 = 12b^2
a^2 = 6b^2
etc.

sqrt(6) won't result in an integer. So there shouldn't be two even integers.
 Sep 4, 2013

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