Lagrange's Interpolation Formula

 #include<stdio.h>  
 #include<math.h>  
 void main()  
 {  
      float ax[10],y[10];  
      float x,numsum=1,densum=1,k;  
      int i,j,n;  
      printf("Enter the number of terms ");  
      scanf("%d",&n);  
      printf("\n=======================================================\n");  
      printf("Enter the array ax ");  
      for(i=0;i<n;i++)  
      {  
           printf("\nEnter the value of ax[%d] = ",i);  
           scanf("%f",&ax[i]);  
      }  
      printf("\n=======================================================\n");  
      for(i=0;i<n;i++)  
      {  
           printf("Enter the value of y[%d] = ",i);  
           scanf("%f",&y[i]);  
      }  
      printf("\nEnter the interpolation point ");  
      scanf("%f",&x);  
      k=0;  
      for(i=0;i<n;i++)  
      {  
           numsum=1;  
           densum=1;  
           for(j=0;j<n;j++)  
           {  
                if(i!=j)  
                {  
                     numsum=numsum*(x-ax[j]);  
                     densum=densum*(ax[i]-ax[j]);  
                }  
           }  
           k=k+(numsum/densum)*y[i];  
      }  
      printf("\nValue at %f is %f ",x,k);  
      getchar();  
 }