I wih prove (sqrt(2))^3 is irrational number

In summary, The conversation is about proving that (sqrt(2))^3 is an irrational number. The speaker mentions that it should be simple to prove that if a number is rational, then its cube is also rational, and asks if the other person is familiar with Euclid's proof that \sqrt{2} is irrational. The other person then asks for a step by step proof, and the speaker provides links to resources that can be used to prove it.
  • #1
abdulmohsen
2
0
hi well I'm having truple in proving this (sqrt(2))^3 is irrational number!
 
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  • #2
If you think this can be proved by computer science, I can see why!

It should be very simple to prove that if a is a rational number, then so it a3. Do you know Euclid's proof that [itex]\sqrt{2}[/itex] is irrational?
 
  • #3
well i need to prove the whole statement step by step how u proved it is irrational!
 
  • #5
use Irrational_check(sqrt(2)^3)
 

1. What is an irrational number?

An irrational number is a number that cannot be expressed as a fraction of two integers. It is a non-repeating, non-terminating decimal. Examples of irrational numbers include pi (π) and the square root of 2 (√2).

2. How do you prove that (sqrt(2))^3 is irrational?

To prove that (sqrt(2))^3 is irrational, we will use proof by contradiction. We will assume that (sqrt(2))^3 is rational, meaning it can be expressed as a fraction of two integers. Then, we will manipulate the equation and show that it leads to a contradiction, proving that our initial assumption was false.

3. Can you provide an example of a proof by contradiction for (sqrt(2))^3 being irrational?

Yes, here is an example of a proof by contradiction for (sqrt(2))^3 being irrational:

Assume that (sqrt(2))^3 is rational and can be expressed as a fraction a/b, where a and b are integers with no common factors.

Then, we can rewrite the equation as (sqrt(2))^3 = a/b.

Raising both sides to the power of 2, we get 2^3 = (a/b)^2.

This simplifies to 8 = a^2/b^2.

Since 8 is an integer, a^2/b^2 must also be an integer.

However, this leads to a contradiction because the square root of 2 (√2) is irrational, meaning it cannot be expressed as a fraction of two integers. Therefore, our initial assumption was false and (sqrt(2))^3 is irrational.

4. Is there another way to prove that (sqrt(2))^3 is irrational?

Yes, there are other ways to prove that (sqrt(2))^3 is irrational. One method is to use the decimal expansion of (sqrt(2))^3 and show that it is non-repeating and non-terminating. This can be done using long division or by showing that the decimal expansion does not follow a specific pattern.

5. Why is proving (sqrt(2))^3 irrational important in science?

Proving that (sqrt(2))^3 is irrational is important in science because it helps us understand the nature of numbers and their properties. It also shows that certain mathematical concepts, such as irrational numbers, cannot be fully explained or represented using simple fractions. This has implications in various fields of science, including physics, chemistry, and engineering.

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