User:Neil Newell

For talk page on [Approximations of pi]

Ref: Pi, a source book By Lennart Berggren, Jonathan M. Borwein, Peter B. Borwein p682

Madhava of Sangamagrama ('Middle Ages')
In this section, it states:

The other method he used was to add a remainder term to the original series of π.

As I understand it, the actual remainder term is either added or subtracted according to whether n is odd or even, i.e. (-1)n*R.