C Program for Quadratic Interpolation

/*Quadratic Interpolation*/




#include<stdio.h>

#include<conio.h>

void main()

{

float x,b0,b1,b2,x0,x1,x2,f,f0,f1,f2;

clrscr();

puts("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");

puts("Quadratic Interpolation");

puts("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");

printf("Enter value of x0,f(x0)");

scanf("%f %f",&x0,&f0);

puts("----------------------------------------");

printf("Enter value of x1,f(x1)");

scanf("%f %f",&x1,&f1);

puts("----------------------------------------");

printf("Enter value of x2,f(x2)");

scanf("%f %f",&x2,&f2);

puts("----------------------------------------");

printf("Enter value of x");

scanf("%f",&x);

puts("----------------------------------------");

b0=f0;

b1=(f1-f0)/(x1-x0);

b2=(((f2-f1)/(x2-x1))-((f1-f0)/(x1-x0)))/(x2-x0);

f=b0+b1*(x-x0)+b2*(x-x0)*(x-x1);

printf("b0=%f\nb1=%f\nb2=%f\nf(x)=%f",b0,b1,b2,f);

puts("\n----------------------------------------");

getch();

}




Output:-

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

Quadratic Interpolation

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

Enter value of x0,f(x0)

1 0

----------------------------------------

Enter value of x1,f(x1)

4 1.5863

----------------------------------------

Enter value of x2,f(x2)

6 1.7918

----------------------------------------

Enter value of x

2

----------------------------------------

b0=0.000000

b1=0.528767

b2=-0.085203

f(x)=0.699173

----------------------------------------