Is "pi" rational or irrational?

Question

How do we not know that it stops at some 19 trillion decimal places.

I know that from what I learned it is irrational, but sometimes I kind of have some doubts.

Answer 1

you may prove that pi = lim (n/2) sin(360/n ) when n goes to infinity .-

So, n has no limit ( Infinity ) , then pi can´t be wrote like Pi = a/b , then is irrational NO DOUBT .-

Answer 2

Because π is an irrational number, its decimal representation does not repeat, and therefore does not terminate. This sequence of non-repeating digits has fascinated mathematicians and laymen alike, and much effort over the last few centuries has been put into computing ever more of these digits and investigating π's properties.[23] Despite much analytical work, and supercomputer calculations that have determined over 1 trillion digits of the decimal representation of π, no simple base-10 pattern in the digits has ever been found.[24] Digits of the decimal representation of π are available on many web pages, and there is software for calculating the decimal representation of π to billions of digits on any personal computer.

Answer 3

pi is irrational



a rational number can be written as a fraction

- any terminating or repeating decimal is rational



an irrational number cannot be written as a fraction

- any non-terminating, non-repeating decimal is irrational

- in other words, it goes on forever without repeating

Answer 4

we assume it is irrational because the billions of decimal places we have calculated have showed no sign of repeating or terminating, we can never be 100% sure though because we would have to calculate it to its last decimal place which would take an infinite amount of time if it were indeed irrational.

Answer 5

it is irrational



there are many proofs to confirm this



the decimal representation does not stop (ever). Otherwise it would be rational.



advanced technology (esp. computers) have determined its value to many (19 trillion?) decimal places, but it is a number that (in decimal format) continues forever... without a continuous repeating sequence of digits.

Answer 6

It is irrational as it is never ending(as far as we know and know it to billions of places)

Answer 7

you can use Archimedes's method(which is still in use today to determine some million digits of pi) some billion trillion times to see for yourself whether it stops or not (i highly doubt it)

Answer 8

Rational means it can be expressed as a ratio that is a fraction. 22/7 is sometimes used as that fraction but it isn't pi

So it isn't rational.

Answer 9

It is irrational, and there are several proofs on Wikipedia.

Answer 10

it is rational, but its just an extremely long number. An irrational number would be like the fraction 1/3. It would be 0.333333333333333333333333 and continue on forever.

Answer 11

irrational