## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$\{t\in \mathbb{R}\ |\ 0\leq t\leq 5\}$ or $[0,5]$
If a function is used as a model for an application, the problem situation may require restrictions on the domain. For example, length and time are generally nonnegative, and a person's age does not increase indefinitely. $V(t)=250-50t\quad$ can be calculated for any real number t, but the sense of the problem is that we take only a nonnegative amount of time into account. So, $t\geq 0.$ Also, the value $V(t)$ should not be negative, so we restrict t in terms of $250-50t\geq 0$ $250\geq 50t$ $5\geq t$ Domain = $\{t\in \mathbb{R}\ |\ 0\leq t\leq 5\}$ or $[0,5]$