Prog qui plante a la fin a cause du free (C)

float *x=NULL;                   // We initialize the pointer x
float *y=NULL;                   // We initialize the pointer y

int main () {                                    // Main function
int i = 0;

    printf ("Please enter N :") ;                // We ask the user to enter the number of x-y pairs he wants to give
    scanf ("%d", &n) ;
    
    x = (float *) malloc(n*sizeof(int));         // We allocate a area in the memory for x
    y = (float *) malloc(n*sizeof(int));         // We allocate a area in the memory for y

    for (i=1;i<=n;i++)                           // Loop of the number of pairs N
        {           
            printf ("Please choose the value of x[%d] :\n", i) ;         // We ask the user for the value of x for each pair
            scanf ("%f", &x[i]) ;         
            printf ("Please choose the value of y[%d] :\n",i) ;   // We ask the user for the value of y for each pair
            scanf ("%f", &y[i]) ; 
        }

D = D_calc(n,x);         // We call the function which calculates D
A = A_calc(n,x,y);       // We call the function which calculates a
B = B_calc(n,x,y);       // We call the function which calculates b
L= - (B/A);              // We calculate L

float D_calc (int n, float *x){                   // Function which calculate the value of D
      int i;
      float D1=0, D2=0, D;
            for (i=1 ; i<=n ; i++){
            D1 = D1 + x[i] * x[i];                // D1 is the first sum of D-equation
            D2 = D2 + x[i];                       // D2 is the second sum of D-equation
            }
        
      D1 = D1 * n;                                // We multiply the first sum of D-equation by n
      D2 = D2 * D2;                               // We put at the power 2 the second part of D-equation
      D = D1 - D2;                                // We finally calculate D
      return (D);
}    

 scanf ("%f", x[i]) ;