How many pi values are there?

Answer 1

There's only one value for pi. If you mean to how many decimal places it has been calculated to, then according to the web site below, 1,240,000,000,000 places.

Answer 2

Exactly one. Pi is a *constant* -- it never changes. There is no pi for you, pi for me, pi for somebody else. There is no pi for the morning and another for night. It is always exactly the same at all times, for all people, in all places. It is the ratio of a circle's circumference to its diameter.

Perhaps the hardest thing for the beginning learner to understand about pi is that the best way to write pi is, well, "pi" (or π, the Greek letter itself, which may or may not look right on your computer screen, sorry). You want to know what pi "really" is. You have a better feeling when somebody tells you that it is *close to* 3.14. That's correct but it's not exact. That's like saying that my house is next to your house. It may be true but it doesn't mean we live together.

There are many numbers with special symbols, like /e/. Some can never be written any better any other way.

Some people think there *must* be a way to write pi using Arabic numerals alone. There isn't. That is a huge, baffling idea. Pi, unlike, say, 12.34, is a *transcendental* number. Transcendental numbers are all *irrational*, which means that you cannot write them as a fraction, the ratio of two integers, or as a decimal. You can only ever write an approximation this way.

It is not even possible to *construct* a line equal to pi using classical compass and straightedge methods. Many have tried, all have failed, and it has been proven impossible.

There are, of course, infinitely many approximations. The only question is: How close do you want to get to the exact value? You may think 3 is close enough. A good approximation is 22 / 7 -- more than good enough for most everyday purposes, like figuring out how much wallpaper to buy for the walls of a round room. Engineers commonly approximate using 3.1416, which is closer but still not exact. The fraction 355 / 113 is still better and pretty easy to remember for such high degrees of precision and accuracy -- but it's not exact.

Here is a 50 decimal place approximation of pi:

3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510

That is a very, very good approximation. There is nothing you will ever do in your life that requires one that is any better. But it is still not exact. It's just a little too small.

The only exact value for pi is pi itself -- just as the only exact value for 3 is 3. It's just a number.

Answer 3

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Answer 4

I have the feeling you are wondering about the difference between all the numerical values commonly assigned to pi since it's almost impossible to get the exact number.

The ones I've seen the most are 22/7, 3.14, and 3.142
but then there it would be possible to keep going with all the decimal places, so you could say that there are an infinite number of pi values that are used, but only one real pi value in concept.

Answer 5

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Answer 6

The mathematical constant π is an irrational real number, approximately equal to 3.14159, which is the ratio of a circle's circumference to its diameter in Euclidean geometry, and has many uses in mathematics, physics, and engineering. It is also known as Archimedes' constant (not to be confused with an Archimedes number) and as Ludolph's number.

The numerical value of π truncated to 50 decimal places is:

3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510
While the value of pi has been computed to hundreds of millions of digits, practical science and engineering will rarely require more than 100 digits. As an example, computing the circumference of the Milky Way with a value of pi truncated at 40 digits would produce an error margin of less than the diameter of a proton. On the other hand, occasionally to produce accurate final results, some calculations may require more accurate intermediate values. Even so, a value of pi longer than a few hundred digits should never be necessary.[2] The exact value of π has an infinite decimal expansion: its decimal expansion never ends and does not repeat, since π is an irrational number (and indeed, a transcendental number). This infinite sequence of digits has fascinated mathematicians and laymen alike, and much effort over the last few centuries has been put into computing more digits and investigating the number's properties. Despite much analytical work, and supercomputer calculations that have determined over 1 trillion digits of π, no simple pattern in the digits has ever been found. Digits of π are available on many web pages, and there is software for calculating π to billions of digits on any personal computer.

Answer 7

That's a complicated way to ask that question, and that's why you're getting different answers. The concept "pi" has only one value. It's an infinite decimal amount, not unlike 1/9 (.1111111 etc). The difference is that the sequence of numbers is seemingly random - no one has figured out a way to calculate the next number and the next, you just have to memorize it.

So, there's only one "pi", but there are infinite numbers in it.

Answer 8

I am sure there is only one value of Pi but as Sandra panda said different people will give you different values of it.

It is the ratio of a radius to circumference or area of a circle.

Sorry to be bit vague but there are a lot of complex issues with pi as I'm sure you can see. If you let us know why you're asking the question maybe we can give you a better answer :-)

Answer 9

Pi only has one value. There are a number of approximations (22/7, 3.14, 355/113...) but these are NOT equal to pi, they are just close enough for every day usage

Answer 10

Just one. Pi is a number, a constant. An irrational number