#include <cstdio>
#include <cmath>
#include <conio.h>

main() {
    int n;
    double a, b, h, r, k, S, Y, x, YS;

    printf("Enter a, b, h, n\n");
    scanf("%lf %lf %lf %d", &a, &b, &h, &n);

    for (x = a; x <= b; x += h;) {
        S = 0;

        for (k = 1; k <= n; k++) S += (pow(x,k)*cos(k*M_PI/3))/k;

        Y = -0.5*log(1-2*x*cos(M_PI/3)+pow(x,2));
        YS = fabs(S-Y);

        printf("\n x = %2.4lf S(x) = %2.6lf Y(x) = %2.6lf |Y(x) - S(x)| = %2.6lf\n", x, S, Y, YS);
    }

    getch();
}