- $ D = \\\left( { - \\\frac{1}{2}; + \\\infty } \\\right)\\\backslash \\\left\\\{ 3 \\\right\\\}$.
- $ D = \\\mathbb{R}$.
- $ D = \\\left( {\\\frac{1}{2}; + \\\infty } \\\right)\\\backslash \\\left\\\{ 3 \\\right\\\}$.
- $ D = \\\left[ {\\\frac{1}{2}; + \\\infty } \\\right)\\\backslash \\\left\\\{ 3 \\\right\\\}$.