Unnamed

#include <stdio.h>
#include <math.h>
#define PI 3.1415927


long int factorial(int n)
{
        if (n<=1)
        return(1);
  else
        n=n*factorial(n-1);
        return(n);
 }

int main (void)
{
        int answer, x, expon, test, sums, next_term;
        float  z, error;
        double  y = 2/(sqrt(PI));
        long int factorial(int n);


        printf("Enter a number :");
        scanf("%i",&answer);
                if( answer == 0) {      //if answer is 0 the error is 0
                        printf("The error is : 0 \n \n");
                }       //if block ends
        else {
                for (expon = 3; expon < 6; expon = expon + 2){
                        for (x = 0; x <= 4; ++x){
                                if ( x % 2 != 0) {
                                        answer = answer * -1;
                                }
                                else{
                                        answer = answer * 1;
                        z = z + (pow(answer,expon))/(expon * factorial(x));
                                        //if block ends
                                }       //else block ends
                        error = y * z;

                        test =  pow(answer,1);
                        next_term = pow(answer,expon);
                        sums = test + next_term;

                }       //for block ends for exponent
                }       // for block ends for factorial

        printf("Error = %i \n", sums);
        }

        return 0;
}