بهازای کدام مقدار $a$ تابع با ضابطهی $f\left( x \right)=\left\{ \begin{matrix}
\frac{a\left( 1+\sqrt[3]{1-x} \right)}{{{x}^{2}}-2x}\,\,\,\,\,\,\,\,\,\,\,\,;\,\,\,\,\,\,\,\,\,x\gt 2 \\
x-a\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,;\,\,\,\,\,\,\,\,\,x\le 2 \\
\end{matrix} \right.$ همواره پیوسته است؟