Should it be?

Question

C++ / C#

Hello.
A simple task, but somehow something ..

spoiler

The left side should match the right side.
Instead of infinity, you can take 100.

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

int main()
{
    double x;
    double resultForLN = 0, resultForSum = 0;

    printf("Enter X : ");
    scanf("%g",&x);

        resultForLN = log( (1.0 + x) / (1.0 - x) );
    printf("%g",resultForLN); // Левый результат

    for (int k = 1; k < 100; k++)
        resultForSum += pow(x, (2.0 * k - 1.0)) / (2.0 * k - 1.0);
    printf("\n%g",resultForSum * 2.0); // Правый результат
}

Answer 1

You have an error in scanf.
%lgworks too - at least on MinGW.
Little is known, but scanf has a slightly different substitution format than printf.

Answer 2

Forget about float, always use double by default.
You calculate x^197 / 197 at the end. Even with x = 2, this will not fit into the float.

Answer 3

Works great on numbers less than unity.