Let \( f \) be a real valued function, defined on \( \mathbb{R}-\{-1,1\} \) and given by \( f(x)=3\log_e \left|\dfrac{x-1}{x+1}\right|-\dfrac{2}{x-1} \). Then in which of the following intervals, function \( f(x) \) is increasing?
\( (-\infty,\infty)-\{-1,1\} \)
\( (-\infty,\tfrac{1}{2}]-\{-1\} \)
\( (-\infty,-1)\,\cup\,\big([\tfrac{1}{2},\infty)-\{1\}\big) \)
\( (-1,\dfrac{1}{2}] \)