Maths-
General
Easy
Question
Show that
is an irrational number
Hint:
Hint:
The real numbers which cannot be expressed in the form of p/q(where p and q are integers and q ≠ 0) are known as irrational numbers. In the given question we are asked to prove if
is irrational number. To do so we use the method of contradiction.
The correct answer is: Is an irrational number.
Let's assume that
is a rational number.
Step 1 of 2:
If
is rational, that means it can be written in the form of p/q, where p and q integers that have no common factor other than 1 i.e. they are coprime than 1 and q ≠ 0.
So ,
Squaring both sides
............(1)

This means p2 can be divided by 4
Step 2 of 2:
So if p2 can be divided by 4, then p can also be divided by 4
So, let’s say 
Squaring both sides

Putting the value of p2 in equation (1)

So, this means q² is divisible by 4 and so q is also divisible by 4.
Final Answer: p and q both are divisible 4 but we assumed that p and q are coprime and this contradiction has arisen because of our incorrect assumption that is a rational number. So, we conclude that
is an irrational number.
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