/******************************************************
 * MT285 TMA03 q3b.cpp
 * Pi calculator by recursion (evaluatePIRecursive())
 * programming by Allen Lam (99043953)
 * compiled by gcc
 * Mar 2001
 ******************************************************/

/*
 * find sum of 1/1 + 1/3^2 + 1/5^2 + 1/7^2 +... up to nth term
 */
double sum_recursive(long n){
  if (n==0) return 0.0; else
  return sum_recursive(n-1) + 1/pow((2.0*n)-1, 2);
}

/*
 * the recursive part is implemented in sum_recursive()
 */
double evaluatePIRecursive(long n){
  return sqrt(sum_recursive(n) * 8);
}

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