prove that √7 is irrational
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0
Answer:
when the number have square root on it's head is root. √7 is the irrational number
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Mark as Brainlist answer.
Step-by-step explanation:
Let us assume that
7 is rational. Then, there exist co-prime positive integers a and b such that
√7=a/b
⟹a=b√7
Squaring on both sides, we get
a^2=7b^2
Therefore, a^2 is divisible by 7 and hence, a is also divisible by 7
so, we can write a=7p, for some integer p.
Substituting for a, we get 49p^2=7b^2⟹b^2=7p^2.
This means, b^2 is also divisible by 7 and so, b is also divisible by 7.
Therefore, a and b have at least one common factor, i.e., 7.
But, this contradicts the fact that a and b are co-prime.
Thus, our supposition is wrong.
Hence,
√7 is irrational.
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