# How do you find the domain and range and determine whether the relation is a function given :y=3x?

##### 1 Answer
Dec 17, 2017

Domain: $x \in \mathbb{R}$
Range: $y \in \mathbb{R}$

#### Explanation:

To find the domain, we look at where the function is defined with real numbers. In this case, all values are defined, so we get a domain of all real numbers, $\mathbb{R}$.

The range is also pretty straight forward. Since the function goes from $- \infty$ to $\infty$ and it is continuous, we know that all real numbers are represented on the graph, so the range must also be all real numbers, $\mathbb{R}$.