prove thae following as irrational number √3+√7
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Answered by
3
Step-by-step explanation:
√3+√7 Let a rational no.
equal to p/q where q =0
√3+√7=p/q
√3=p/q-√7
squaring both sides
p^2/q^2+7-2p/q√7=3
p^2/q^2+4=2p/q√7
p/q+4=2√7
p/q+2=√7
p/q +2 is a rational number
√7 is a irrational number
a rational number and a irrational number can never be equal so our supposition is wrong
Hence proved that √3+√7 is a irrational number
Answered by
2
Let us assume the opposite, that 3+√7 is rational.
Hence, 3+√7 can be written in the form a/b
where a and b are co-prime and b is not equal to 0.
Hence, 3+√7=a/b
= √7=a/b-3
=√7= a-3b/b
where √7 is irrational and a-3b/b is rational.
Since, rational is not equal to irrational.
This is a contradiction.
Our assumption is incorrect.
Hence, 3+√7 is irrational.
Hence proved.
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