Taylor series expansion of cos(x) with a given accuracy 

**eps**
**Recursive approach**

> 
> [Error] overloaded function with no contextual type information
> 
> 
> 

How can I fix this error?

[Photo1](http://i.stack.imgur.com/qEKpc.png)

```
#include <stdio.h>
#include <math.h>

double cos(double x, double eps, double s=0,double n=0,double a=0) {
    if (abs(n)<1){
    cos=cos(x, eps,1,1,1);
}
else {
    a = -a*x*x / ((2*n-1) * (2*n));
    if (abs(a)<=eps) {
        cos=s;
    }
    else{
        cos=cos(x, eps, s+a, a,n+1);
    }
  }
} 
int main () {
    double x;
    scanf("%f", &x);
    cos(x, 0.000000000000001);
}

```