Hello guys !
I have this homework .. my instructor wants us to solve the following question using c++
Determine the value of F(x) using lagrange polynomials method for the following data
Xi=-1.5 , -0.75 , 0 , 0.75 ,1.5
Yi=-14.1014 , -0.931596 , 0 , 0.931596, 14.1014
Here is my code .. but it only finds the summation , I guess I have to define some character value to use it in printing the formula F(x),, but I couldn't apply this idea .. any help ??
where x=1.4 , and sum will equal to 11.1984
I have this homework .. my instructor wants us to solve the following question using c++
Determine the value of F(x) using lagrange polynomials method for the following data
Xi=-1.5 , -0.75 , 0 , 0.75 ,1.5
Yi=-14.1014 , -0.931596 , 0 , 0.931596, 14.1014
Here is my code .. but it only finds the summation , I guess I have to define some character value to use it in printing the formula F(x),, but I couldn't apply this idea .. any help ??
Rich (BB code):
#include <iostream.h>
#include <stdlib.h>
#include <math.h>
void main ()
{
double X[5],Y[5];
double n=5,sum=0,x;
cout <<"Insert the value x: \n";
cin >>x;
cout <<"Enter vector X : \n" ;
for (int a=0;a<n;a++)
{
cin>>X[a];
cout <<X[a]<<endl;
}
cout<<endl;
cout <<"Enter vector Y : \n" ;
for (int b=0;b<n;b++)
{
cin>>Y;
cout <<Y<<endl;
}
cout<<endl;
for (int i=0;i<n;i++)
{
double p=1;
for (int j=0;j<n;j++)
{
if (j!=i)
{
p=p*((x-X[j])/(X-X[j]));
}
}
sum=sum+p*Y;
}
cout <<"SUM = \n " << sum <<endl;
}
where x=1.4 , and sum will equal to 11.1984