# What is the domain of f(x)=7x+4?

Mar 18, 2018

$x \in \mathbb{R}$

#### Explanation:

This is just the equation of a line, where $7$ is the slope and $4$ is the y-intercept, so the function is continuous.

Since our function $f \left(x\right)$ is continuous, its domain is $x \in \mathbb{R}$, meaning $x$ can take on any value.

• You can plug in $2$ for $x$ and get a value for $f \left(x\right)$
• You can plug in $81$ for $x$ and get a value for $f \left(x\right)$
• You can plug in $5341238$ in for $x$ and get a value for $f \left(x\right)$

The point is, no input for $x$ will make this function undefined, thus its domain is $x \in \mathbb{R}$.