/* ATK IV NUMERICAL PROGRAMMING (2006) */ /* Subroutine for Excercise 2.4 - Cosine power series */ #include #include #define Pi 3.141592654 double cosine(double x, int n){ int i; double step = 1.0; double sum = 1.0; x = fmod(x,2*Pi); /* Calculates x(mod 2Pi) */ for(i=1;i<=n;i++){ step *= -1.0*x*x/(2.0*i*(2.0*i-1.0)); sum += step; } return sum; }