RunKut()

void RunKut(double a, double b, double h, double y0, double(*f)(double, double), FILE *file) {
    double x = a, y = y0;


    while (x <= b) {
        y = y + ((f(x, y)+ f(x+h, y+h))*h)/2.0;
        fprintf(file, "%10.5lf %10.5lf\n", x, y);
        x += h;
    }

    fprintf(file, "\n");
}