1. The problem asks for the domain of variables $a$ and $b$. 2. The domain of a variable is the set of all possible values it can take. 3. Without additional context or constraints, $a$ and $b$ are typically assumed to be real numbers. 4. Therefore, the domain of $a$ is $\mathbb{R}$ (all real numbers). 5. Similarly, the domain of $b$ is $\mathbb{R}$ (all real numbers). 6. If there are specific conditions or equations involving $a$ and $b$, those would restrict their domains accordingly. 7. In summary, without further information, the domains are: $$\text{Domain of } a = \mathbb{R}$$ $$\text{Domain of } b = \mathbb{R}$$