Who ordered that pi ?

Srinivasa Ramanujan was a self-taught Indian mathematician, who worked as a clerk in Madras (now Chennai). One of Ramanujan’s contributions was the method to work out the infinite series of pi. His work shows an extraordinary intuition about the properties of numbers including pi and his most well know formula is:

The  ∞∑n=0 symbol indicates the sum of a series, starting with n equals zero added to the value when n equals one and so on to infinity. Even if you do not understand the notation, the beauty of the equation lies in the fact that the speed at which it approaches pi. When n is equal to zero, the formula has one term and gives a value of pi accurate to six decimal places. For each increase in the value of n, the formula adds roughly eight new digits to pi. Some call this formula an industrial strength pi-making machine. Today mathematicians have improved on this formula to churn out bigger and bigger values of pi.

Prior to Ramanujan, mathematicians were using formula devised by Leonard Euler (pronounced ‘oiler’) to derive the value of pi, to larger and larger decimal places. Euler was a prolific mathematician and a writer, publishing up to 886 books. Some of the mathematical notations we use today were devised by him, including e, π and i (root of-1) One of the equations he derived was:

e^πi +1 = 0  

Known as Euler’s Identity, it links together what mathematicians call as the five most important constant in mathematics- e , i, π , 0 and 1. It also uses the operations of addition, multiplication and exponentiation exactly once each. Many publications have chosen this as the ‘most beautiful’ or ‘the greatest equation ever’.