#Arithmetic
Pi (or π) is the most widely known mathematical symbol. It is used in formulas involving circles, geometry, trigonometry or periodic motion, and even in some fundamental physical constants. But what does it signify?
For any circle no matter what size, the ratio of the circumference to its diameter is ALWAYS the same. It is a constant. This property has been identified since centuries, and the value is called pi (or π).
So what exactly is pi’s value? Nobody knows or will ever know! The fascinating thing about pi is that it is an irrational number — it cannot be expressed as a fraction and its decimal expansion never ends and never repeats. This means that the exact value is never known, as the number never ends! Ancient mathematicians found this concept of never ending numbers completely maddening!
The first 100 digits of pi are:
3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510 58209 74944 59230 78164 06286 20899 86280 34825 34211 7067
The first rigorous calculation of pi was done by Archimedes (287–212 BC), one of the greatest mathematicians of the ancient world. He showed that pi is between 3 1/7 and 3 10/71. However, it has been approximately known since much before, to calculate areas and circumferences of circular objects. The ancient Babylonians (1900–1680 BC) approximated pi as 3.125, the Indians (500–400 BC) used 3.139, while the Egyptians (1850 BC) used the value of 3.1605 for pi.
How much pi is enough pi? The decimal of pi till 39 digits is enough to estimate the circumference of any circle within the observable universe with precision comparable to the radius of a hydrogen atom. NASA uses 15–16 digits of pi for its expeditions. At position 763, there are six 9s in a row. This is known as the Feynman point. The highest computation for pi’s value is upto more than a trillion digits.
