I will give 10 points to the person who gives me the most info about pi?

kindly visit following link . you will get all the details about pi

http://en.wikipedia.org/wiki/Pi

From above you get following information .i think it is sufficient for you

Contents [hide]

1 The letter π

2 Definition

3 Numerical value

3.1 Calculating π

4 Properties

5 History

5.1 Use of the symbol π

5.2 Early approximations

6 Numerical approximations

7 Formulæ

7.1 Geometry

7.2 Analysis

7.3 Continued fractions

7.4 Number theory

7.5 Dynamical systems and ergodic theory

7.6 Physics

7.7 Probability and statistics

7.8 Efficient methods

7.9 Miscellaneous formula

8 Memorising digits

9 Open questions

10 Naturality

11 Fictional references

12 Trivia

13 See also

14 References

14.1 Footnotes

14.2 Additional

3.1415926535897932384626433832795 (roughly 22/7)

By definition, pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter which circle you use to compute it.

For the sake of usefulness people often need to approximate pi. For many purposes you can use 3.14159, which is really pretty good, but if you want a better approximation you can use a computer to get it. Here's pi to many more digits:

The area of a circle is pi times the square of the length of the radius, or "pi r squared":

A = pi*r^2

A very brief history of pi

Pi is a very old number. We know that the Egyptians and the Babylonians knew about the existence of the constant ratio pi, although they didn't know its value nearly as well as we do today. They had figured out that it was a little bigger than 3; the Babylonians had an approximation of 3 1/8 (3.125), and the Egyptians had a somewhat worse approximation of 4*(8/9)^2 (about 3.160484), which is slightly less accurate and much harder to work with. For more, see A History of Pi by Petr Beckman (Dorset Press).

The modern symbol for pi [] was first used in our modern sense in 1706 by William Jones, who wrote:

There are various other ways of finding the Lengths or Areas of particular Curve Lines, or Planes, which may very much facilitate the Practice; as for instance, in the Circle, the Diameter is to the Circumference as 1 to (16/5 - 4/239) - 1/3(16/5^3 - 4/239^3) + ... = 3.14159... = (see A History of Mathematical Notation by Florian Cajori).

Pi (rather than some other Greek letter like Alpha or Omega) was chosen as the letter to represent the number 3.141592... because the letter [] in Greek, pronounced like our letter 'p', stands for 'perimeter'.

About Pi

Pi is an infinite decimal. Unlike numbers such as 3, 9.876, and 4.5, which have finitely many nonzero numbers to the right of the decimal place, pi has infinitely many numbers to the right of the decimal point.

If you write pi down in decimal form, the numbers to the right of the 0 never repeat in a pattern. Some infinite decimals do have patterns - for instance, the infinite decimal .3333333... has all 3's to the right of the decimal point, and in the number .123456789123456789123456789..... the sequence 123456789 is repeated. However, although many mathematicians have tried to find it, no repeating pattern for pi has been discovered - in fact, in 1768 Johann Lambert proved that there cannot be any such repeating pattern.

As a number that cannot be written as a repeating decimal or a finite decimal (you can never get to the end of it) pi is irrational: it cannot be written as a fraction (the ratio of two integers).

Pi shows up in some unexpected places like probability, and the 'famous five' equation connecting the five most important numbers in mathematics, 0, 1, e, pi, and i: e^(i*pi) + 1 = 0.

Computers have calculated pi to many decimal places. Here are 50,000 of them and you can find many more from Roy Williams' Pi Page.

3.14159265358979323846.

By definition, pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter which circle you use to compute it.

For the sake of usefulness people often need to approximate pi. For many purposes you can use 3.14159, which is really pretty good, but if you want a better approximation you can use a computer to get it. Here's pi to many more digits: 3.14159265358979323846.

The area of a circle is pi times the square of the length of the radius, or "pi r squared":

A = pi*r^2

A very brief history of pi

Pi is a very old number. We know that the Egyptians and the Babylonians knew about the existence of the constant ratio pi, although they didn't know its value nearly as well as we do today. They had figured out that it was a little bigger than 3; the Babylonians had an approximation of 3 1/8 (3.125), and the Egyptians had a somewhat worse approximation of 4*(8/9)^2 (about 3.160484), which is slightly less accurate and much harder to work with. For more, see A History of Pi by Petr Beckman (Dorset Press).

The modern symbol for pi [] was first used in our modern sense in 1706 by William Jones, who wrote:

There are various other ways of finding the Lengths or Areas of particular Curve Lines, or Planes, which may very much facilitate the Practice; as for instance, in the Circle, the Diameter is to the Circumference as 1 to (16/5 - 4/239) - 1/3(16/5^3 - 4/239^3) + ... = 3.14159... = (see A History of Mathematical Notation by Florian Cajori).

Pi (rather than some other Greek letter like Alpha or Omega) was chosen as the letter to represent the number 3.141592... because the letter [] in Greek, pronounced like our letter 'p', stands for 'perimeter'.

About Pi

Pi is an infinite decimal. Unlike numbers such as 3, 9.876, and 4.5, which have finitely many nonzero numbers to the right of the decimal place, pi has infinitely many numbers to the right of the decimal point.

If you write pi down in decimal form, the numbers to the right of the 0 never repeat in a pattern. Some infinite decimals do have patterns - for instance, the infinite decimal .3333333... has all 3's to the right of the decimal point, and in the number .123456789123456789123456789... the sequence 123456789 is repeated. However, although many mathematicians have tried to find it, no repeating pattern for pi has been discovered - in fact, in 1768 Johann Lambert proved that there cannot be any such repeating pattern.

As a number that cannot be written as a repeating decimal or a finite decimal (you can never get to the end of it) pi is irrational: it cannot be written as a fraction (the ratio of two integers).

Pi shows up in some unexpected places like probability, and the 'famous five' equation connecting the five most important numbers in mathematics, 0, 1, e, pi, and i: e^(i*pi) + 1 = 0.

Computers have calculated pi to many decimal places. Here are 50,000 of them and you can find many more from Roy Williams' Pi Page.

I think someone already got the most decimal places thing. Pi is determined by taking the circumference over the diameter. This is where you get the classic equation C = 2*pi*r = pi*d. And as for history there's a boatload on Wiki

http://en.wikipedia.org/wiki/History_of_Pi

pi?

pi

in mathematics, the ratio of the circumference of a circle to its diameter. The symbol for pi is π. The ratio is the same for all circles and is approximately 3.1416. It is of great importance in mathematics not only in the measurement of the circle but also in more advanced mathematics in connection with such topics as continued fractions, logarithms of imaginary numbers, and periodic functions. Throughout the ages progressively more accurate values have been found for π; an early value was the Greek approximation 31⁄7, found by considering the circle as the limit of a series of regular polygons with an increasing number of sides inscribed in the circle. About the mid-19th cent. its value was figured to 707 decimal places and by the mid-20th cent. an electronic computer had calculated it to 100,000 digits. It would have taken a person working without error eight hours a day on a desk calculator 30,000 years to make this calculation; it took the computer eight hours. Although it has now been calculated to more than 200,000,000,000 digits, the exact value of π cannot be computed. It was shown by the German mathematician Johann Lambert in 1770 that π is irrational and by Ferdinand Lindemann in 1882 that π is transcendental; i.e., cannot be the root of any algebraic equation with rational coefficients. The important connection between π and e, the base of natural logarithms, was found by Leonhard Euler in the famous formula eiπ=−1, where i= [radical]−1.

Circlelengh/radius=Pi

Little eco-friendly leprechauns floating on a cornflake watching the Republicans kill one yet another over scientific care and Johnny Depp and Keira Knightley making out on a stool in a yellow sea of nutrition Water.

Pi is the ratio of the circumberence of a circle to its diameter.

pi = circumference / diameter

Pi character is π

pi decimal approximation is 3.141592654..... an infinite (∞ ) number of non repeating numbers.

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Click on the URL below for additional information

mathforum.org/dr.math/faq/faq.pi.html

en.wikipedia.org/wiki/Pi

Pi (upper case Π, lower case π or ϖ) is the sixteenth letter of the Greek alphabet. In the system of Greek numerals it has a value of 80.

In Greek, the letter is pronounced /piː/ (as in pee); in modern English, it is pronounced /paɪː/ (as the word pie), in particular when referring to the mathematical constant (see below). In words, it is pronounced /p/. In Modern Greek, the sequence of letters μπ represents the /b/ sound, as in boy (the second letter of the Greek alphabet is now pronounced /v/ as in very).

There is another variant of lower case Pi, resembling a lower case Omega: .

The upper-case letter Π is used as a symbol for:

The product operator in mathematics (in analogy to the use of the capital Sigma Σ as summation symbol).

In textual criticism, Codex Petropolitanus, a 9th century, uncial codex of the Gospels, now located in St. Petersburg, Russia.

The lower-case letter π is used as a symbol for:

The mathematical irrational constant π ≈ 3.14159..., the ratio of a circle's circumference to its diameter in Euclidean geometry. In Classical Greek it was also intended as a shorthand for the word perimetros or (περιμετρος) peri meaning "around" and "metros" to measure or measurement. Its equivalent in Latin being the slightly more familiar "circumference".

The prime counting function in mathematics.

Dimensionless parameters constructed using the Buckingham π theorem of dimensional analysis.

The osmotic pressure in chemistry. π=MRT

The elementary particle called the pi meson or pion.

Profit in microeconomics.

Inflation rate in macroeconomics.

A type of chemical bond in which the P-orbitals overlap

In HTML, the capital letter Π can be produced using the codes Π or Π, and the lower-case by using π or π within the source code.

Retrieved from "http://en.wikipedia.org/wiki/Pi_%28letter%29%22

3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067982148086513282306647093844609550582231725359408128481117450284102701938521105559644622948954930381964428810975665933446128475648233786783165271201909145648566923460348610454326648213393607260249141273724587006606315588174881520920962829254091715364367892590360011330530548820466521384146951941511609

The mathematical constant π is a 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 Archimedes number) and as Ludolph's number.