# How do you find the domain and range of h(x) = 3x+9 ?

Jun 7, 2018

Domain $\left\{x | x \text{ is } \mathbb{R}\right\}$ or in interval notation $\left(- \infty , \infty\right)$

Range $\left\{h \left(x\right) | h \left(x\right) \text{ is } \mathbb{R}\right\}$ or in interval notation $\left(- \infty , \infty\right)$

#### Explanation:

$h \left(x\right) = 3 x + 9$ is the equation of a line, the domain and range of all lines have no restrictions and include all real numbers.

Domain $\left\{x | x \text{ is } \mathbb{R}\right\}$ or in interval notation $\left(- \infty , \infty\right)$

Range $\left\{h \left(x\right) | h \left(x\right) \text{ is } \mathbb{R}\right\}$ or in interval notation $\left(- \infty , \infty\right)$

graph{3x+9 [-19.83, 20.17, -5.68, 14.32]}