Math, asked by singhjai12381, 1 month ago

prove that √2 is irrational.​

Answers

Answered by seabird1234
3

Let us assume that √2 is a rational number.

Let us assume that √2 is a rational number.So it can be expressed in the form p/q where p, q are co-prime integers and q≠0

Let us assume that √2 is a rational number.So it can be expressed in the form p/q where p, q are co-prime integers and q≠0√2 = p/q

Let us assume that √2 is a rational number.So it can be expressed in the form p/q where p, q are co-prime integers and q≠0√2 = p/qHere p and q are coprime numbers and q ≠ 0

Let us assume that √2 is a rational number.So it can be expressed in the form p/q where p, q are co-prime integers and q≠0√2 = p/qHere p and q are coprime numbers and q ≠ 0Solving

Let us assume that √2 is a rational number.So it can be expressed in the form p/q where p, q are co-prime integers and q≠0√2 = p/qHere p and q are coprime numbers and q ≠ 0Solving√2 = p/q

Let us assume that √2 is a rational number.So it can be expressed in the form p/q where p, q are co-prime integers and q≠0√2 = p/qHere p and q are coprime numbers and q ≠ 0Solving√2 = p/qOn squaring both the side we get,

Let us assume that √2 is a rational number.So it can be expressed in the form p/q where p, q are co-prime integers and q≠0√2 = p/qHere p and q are coprime numbers and q ≠ 0Solving√2 = p/qOn squaring both the side we get,=>2 = (p/q)²

=> 2q² = p²……………………………..(1)

……………………………..(1)p2/2 = q2

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)From equations (1) and (2), we get,

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)From equations (1) and (2), we get,2q² = 4m²

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)From equations (1) and (2), we get,2q² = 4m²⇒ q² = 2m²

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)From equations (1) and (2), we get,2q² = 4m²⇒ q² = 2m²⇒ q² is a multiple of 2

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)From equations (1) and (2), we get,2q² = 4m²⇒ q² = 2m²⇒ q² is a multiple of 2⇒ q is a multiple of 2

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)From equations (1) and (2), we get,2q² = 4m²⇒ q² = 2m²⇒ q² is a multiple of 2⇒ q is a multiple of 2Hence, p, q have a common factor 2. This contradicts our assumption that they are co-primes. Therefore, p/q is not a rational number

……………………………..(1)p2/2 = q2So 2 divides p and p is a multiple of 2.⇒ p = 2m⇒ p² = 4m² ………………………………..(2)From equations (1) and (2), we get,2q² = 4m²⇒ q² = 2m²⇒ q² is a multiple of 2⇒ q is a multiple of 2Hence, p, q have a common factor 2. This contradicts our assumption that they are co-primes. Therefore, p/q is not a rational number√2 is an irrational number.

Answered by ashishc1403
1

Hello... lets do it cmon...

Let's suppose √2 is a rational number. Then we can write it √2  = a/b where a, b are whole numbers, b not zero.

We additionally assume that this a/b is simplified to lowest terms, since that can obviously be done with any fraction. Notice that in order for a/b to be in simplest terms, both of a and b cannot be even. One or both must be odd. Otherwise, we could simplify a/b further.

From the equality √2  = a/b it follows that 2 = a2/b2,  or  a2 = 2 · b2.  So the square of a is an even number since it is two times something.

From this we know that a itself is also an even number. Why? Because it can't be odd; if a itself was odd, then a · a would be odd too. Odd number times odd number is always odd. Check it if you don't believe me!

Okay, if a itself is an even number, then a is 2 times some other whole number. In symbols, a = 2k where k is this other number. We don't need to know what k is; it won't matter. Soon comes the contradiction.

If we substitute a = 2k into the original equation 2 = a2/b2, this is what we get:

2 = (2k)2/b2

2 = 4k2/b2

2*b2 = 4k2

b2 = 2k2

This means that b2 is even, from which follows again that b itself is even. And that is a contradiction!!!

WHY is that a contradiction? Because we started the whole process assuming that a/b was simplified to lowest terms, and now it turns out that a and b both would be even. We ended at a contradiction; thus our original assumption (that √2 is rational) is not correct. Therefore √2 cannot be rational.

have a grt day ahead buddy...

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