# How do you find the domain of f(x) = |2x + 1|?

Feb 27, 2017

$- \infty < x < \infty$

#### Explanation:

The domain is the set of $x$ values that an equation can take.

The range is the set of $y$ values an equation can spit out.

For $f \left(x\right) = | 2 x + 1 |$, you can put in any $x$ value and get a $y$ out, so the domain is anything:

$- \infty < x < \infty$

However, because it is the ultimate value (or modulus) function, it is the positive distance from zero - in other words, if the output is negative, it becomes positive, and if it is positive, is stays positive.

Therefore, it can only be positive, so the range is:

$f \left(x\right) \ge 0$