[2] viXra:2102.0147 [pdf] submitted on 2021-02-23 13:35:30
Authors: Edgar Valdebenito
Comments: 2 Pages.
In this note we give some series for the expression: S=(pi/4)*R1+R1*arctan(R2)+R3*ln(R4) , R1,R2,R3,R4 reals numbers .
Category: General Mathematics
[1] viXra:2102.0093 [pdf] submitted on 2021-02-15 23:30:32
Authors: Xingfeng Chen
Comments: 9 Pages.
A method for computing the n decimal digits of pi in
O(n) iterations with O (n) computation complexity
and O (1) memory. The key through is that the area
of a circle equals to the sum of the difference of
areas between polygons inside one circle.
Category: General Mathematics