lab4-part

double f(double x, double e) {
    double last_val = -1, current_val = x / 2;
    double sum = current_val;
    int k = 1;
    do {
        last_val = current_val;
        current_val *= x * k / (k + 2);
        sum += current_val;
        k++;
    } while (abs(current_val - last_val) >= e);

    return 1 - sum;
}

double F(double x) {
    return ((1 - x) / x) * log(1 / (1 - x));
}

double delta(double f, double F) {
    return abs(f * f - F * F);
}