Thread: Value of a polynomial in a point

I don't know why this doesn't work. It doesn't return any errors, but it does the polynomial equation wrong. I tried using "^" instead of "pow" and it still does it wrong. I'm getting results like "-897123897" instead of "3". This is the code:

Code:

#include <stdio.h>
#include <conio.h>
#include <math.h>
int main()
{
    int i, x[10], e, S = 0;
    double y;
    printf("Plese insert degree of polynomial\n");
    scanf("%d", &e);
    printf("Please insert X\t");
    scanf("%d", &y);
    printf("Please insert coeficient of each degree\n");
    for (i = 0; i <= e; i++)
    {    
        scanf("%d", &x[i]);
    }
    S = 0;
    for (i = 0; i <= e; i++)
    {
        S = S + x[i]*(pow(y,e-i));
    }
    printf("The value of your polynomial is = %d\n", S);
    getch();
}

It worked! Thank you very much. I lost at least 3 hours on this

Originally Posted by OctavianC

I tried using "^" instead of "pow" and it still does it wrong.

^ is not an exponent operator, it's bitwise exclusive or:

Code:

1 ^ 1 = 0
0 ^ 0 = 0
1 ^ 0 = 1
0 ^ 1 = 1

You weren't going to get a sensible answer by mixing bits.

I'm kind of proud of how much I've learned in two days .