Programming scientific calculation:

how to I write a C fonction that calculate the convergence of pi (3.1415......) with Francois Vieta formula;

The formula work like this

and its partiel sums are

This sould be possible with just one function, loop, and the sqrt(double)

*The number of partiel sum is decided by the parameter for the function ex: double vieta(int n) were n is the number of partiel sums

* Code does not have to be in C code as long I can understand the steps

TE 2, X X