A skate shop rents roller skates as shown in the table below.

Roller Skate Rentals

\begin{tabular}{|c|c|}
\hline Time & Cost \\
\hline up to 60 minutes & [tex]$\$[/tex] 5[tex]$ \\
\hline up to 2 hours & $[/tex]\[tex]$ 10$[/tex] \\
\hline up to 5 hours & [tex]$\$[/tex] 20[tex]$ \\
\hline daily & $[/tex]\[tex]$ 25$[/tex] \\
\hline
\end{tabular}

Which graph and function model this situation, where [tex]$c$[/tex] is the cost, in dollars, for [tex]$t$[/tex] hours in a single day that the skates are rented?

[tex]\[ c(t)=\left\{
\begin{array}{ll}
\$ 5 & \text{if } 0 \ \textless \ t \leq 1 \\
\$ 10 & \text{if } 1 \ \textless \ t \leq 2 \\
\$ 20 & \text{if } 2 \ \textless \ t \leq 5 \\
\$ 25 & \text{if } 5 \ \textless \ t \leq 24
\end{array}
\right. \][/tex]



Answer :

To model the cost of renting roller skates based on the given time intervals, we need to define a piecewise function [tex]\( c(t) \)[/tex] where [tex]\( t \)[/tex] is the rental time in hours, and [tex]\( c(t) \)[/tex] is the cost in dollars. We'll break down the intervals step by step as per the given cost structure:

1. If [tex]\( 0 < t \leq 1 \)[/tex]:
For any time [tex]\( t \)[/tex] between 0 and 1 hour, the cost [tex]\( c(t) \)[/tex] is [tex]\( \$5 \)[/tex].

2. If [tex]\( 1 < t \leq 2 \)[/tex]:
For any time [tex]\( t \)[/tex] between more than 1 hour and up to 2 hours, the cost [tex]\( c(t) \)[/tex] increases to [tex]\( \$10 \)[/tex].

3. If [tex]\( 2 < t \leq 5 \)[/tex]:
For any time [tex]\( t \)[/tex] between more than 2 hours and up to 5 hours, the cost [tex]\( c(t) \)[/tex] further increases to [tex]\( \$20 \)[/tex].

4. If [tex]\( 5 < t \leq 8 \)[/tex]:
For any time [tex]\( t \)[/tex] between more than 5 hours and up to 8 hours, the cost [tex]\( c(t) \)[/tex] is [tex]\( \$25 \)[/tex].

For [tex]\( t \)[/tex] values beyond 8 hours, we assume the rental time exceeds the defined limits, so the cost function does not cover these values.

Given this structure, the piecewise function [tex]\( c(t) \)[/tex] can be written as:

[tex]\[ c(t) = \begin{cases} 5 & \text{if } 0 < t \leq 1 \\ 10 & \text{if } 1 < t \leq 2 \\ 20 & \text{if } 2 < t \leq 5 \\ 25 & \text{if } 5 < t \leq 8 \\ \text{Time exceeds limits} & \text{if } t > 8 \end{cases} \][/tex]

This function reflects the cost structure provided by the skate shop. Each interval corresponds to a specific rental cost, ensuring the model accurately represents the rental pricing for up to 8 hours within a single day. The function also indicates that any rental time beyond 8 hours would exceed the stipulated rental periods provided.