C程序---使用函數計算餘弦函數近似值

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

float funcos(float e, float x);

 int main()
 {
      float e,x,sum;
      printf("input e : ");
      scanf("%f",&e);
      printf("\n");
      printf("input x: ");
      scanf("%f",&x);
      printf("\n");
      sum = funcos(e,x) ;
      printf("sum = %f\n",sum);


      return 0;
 }

float funcos(float e, float x)
{
      float result=1 ,mole=1,deno=1,value = 1;
      int i,j;
      j = -1 ;

            for(i = 2 ;value>e; i+=2)
            {
                  mole = mole*x*x; ;
                  deno = deno * i*(i-1) ;
                  value = mole/deno ;
                  result = result + j*mole/deno ;
                  j = -j ;

            }

      return result ;

}