Is the Square Root of Pi Irrational?

In summary, the conversation discusses a question about proving that pi is irrational. The person asking the question found a proof and a similar one online, but was confused by the solution provided. The summary also states that the proof shows that if pi is irrational, then so is its square root, which is likely what the question was asking.
  • #1
phospho
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A question in my book says to prove that pi is irrational, I found a proof which I'm happy with and found a similar one on the web however on the solutions they have done:

assume √π is rational i.e [tex] \sqrt{\pi} = \frac{p}{q} p,q \in \mathbb{Z} [/tex]
[tex] \pi = \frac{p^2}{q^2}, p^2,q^2 \in \mathbb{Z} ∴ \pi \mathrm{is\ rational} [/tex]

∴ contradiction √π irrational,

could anyone explain how it's a contradiction? I've pasted exactly what they have in the solution
 
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  • #2
The proof shows that if pi is irrational then so is its square root. Presumably that is what the question asked, or intended to ask.
 
  • #3
haruspex said:
The proof shows that if pi is irrational then so is its square root. Presumably that is what the question asked, or intended to ask.

that makes much more sense, heh.
 

1. What is pi and why is it important?

Pi is a mathematical constant that represents the ratio of a circle's circumference to its diameter. It is approximately 3.14159 and is used in many mathematical and scientific calculations involving circles and spheres.

2. How was it proven that pi is irrational?

The proof that pi is irrational was first given by the ancient Greek mathematician Euclid. It involves assuming that pi is a rational number (can be written as a fraction) and then using a logical argument to show that this assumption leads to a contradiction. This shows that pi cannot be expressed as a fraction and is therefore irrational.

3. Why is proving pi irrational significant?

Proving that pi is irrational has important implications in mathematics and science. It shows that there are numbers that cannot be expressed as a finite decimal or fraction, leading to a better understanding of the complexity of numbers. It also has practical applications in fields such as cryptography and computer programming.

4. Are there other ways to prove pi is irrational?

Yes, there are multiple ways to prove that pi is irrational. One approach is to use the continued fraction expansion of pi, which shows that it has an infinite non-repeating decimal representation. Another method is to use the Lindemann–Weierstrass theorem, which states that any number that can be expressed as a root of a non-zero polynomial with rational coefficients must be transcendental (and therefore irrational).

5. Can pi ever be fully calculated or known?

No, pi is an irrational number with an infinite number of digits after the decimal point. While we can calculate it to a very high degree of accuracy using computers, it cannot be fully known or expressed as a finite number. It is an infinitely complex and mysterious number, making it a fascinating subject for mathematicians and scientists.

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