#include <stdio.h>
#include <math.h>

double calculateNaturalLog(double x, int n) {
    if (x <= -1) {
        printf("Error: Natural logarithm is undefined for x <= -1.\n");
        return 0;
    }

    double result = 0.0;
    double term = x;
    int sign = -1;

    for (int i = 2; i <= n; i++) {
        term *= (x * -1);
        result += sign * (term / i);
        sign *= -1;
    }

    return result;
}

int main() {
    double x;
    int n;

    printf("Enter the value of x: ");
    scanf("%lf", &x);

    if (x <= -1) {
        printf("Error: Natural logarithm is undefined for x <= -1.\n");
        return 1;
    }

    printf("Enter the number of terms (n): ");
    scanf("%d", &n);

    double result = calculateNaturalLog(x, n);
    double actualResult = log(1 + x);

    printf("Approximation of ln(1 + %.2lf) using %d terms: %.6lf\n", x, n, result);
    printf("Actual ln(1 + %.2lf) using math.h: %.6lf\n", x, actualResult);

    return 0;
}