How to prove root5 irrational

1.	How to prove root5 irrational
Answer» Let √5 be a rational number then it can be written in the form of a/b where b≠0 , a and b are co prime numbers ... So √5= a/b , now squaring on both sides gives 5=a²/b². 5b² = a² . Now we can say that a² is divisible by 5 then a is also divisible by 5. Let a =5c , squaring on both sides gives a²=25 c². Putting value of a² ... 5b² =25 c²... b²=5c².. so we can say that b² is divisible by 5 then b is also divisible by 5. So our assumption is wrong , so due to contradiction √5 is an irrational number as it a common factor other than a and b . Hence proved.

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