Questions: Solving Quadratic Equations
Select the correct answer
A coffee shop begins the day with 75 bagels and sells an average of 10 bagels each hour. Function b models the bagel inventory, b(x), x hours after opening.
b(x)=75-10x
If the coffee shop wants to make a graph of function b, which values of x should it include on the graph to include the relevant domain within the context?
A. 0 ≤ x ≤ 75
B. -∞ ≤ x ≤ ∞
C. 0 ≤ x ≤ ∞
D. 0 ≤ x ≤ 7.5
Transcript text: Solving Quadratic Equations
Select the correct answer
A coffee shop begins the day with 75 bagels and sells an average of 10 bagels each hour. Function $b$ models the bagel inventory, $b(x)$, $x$ hours after opening.
$b(x)=75-10x$
If the coffee shop wants to make a graph of function $b$, which values of $x$ should it include on the graph to include the relevant domain within the context?
A. $0 \leq x \leq 75$
B. $-\infty \leq x \leq \infty$
C. $0 \leq x \leq \infty$
D. $0 \leq x \leq 7.5$
Solution
Solution Steps
Step 1: Determine the Relevant Domain
The function \( b(x) = 75 - 10x \) models the bagel inventory, where \( x \) is the number of hours after opening. The coffee shop starts with 75 bagels and sells 10 bagels per hour. The relevant domain for \( x \) is the time during which the shop has bagels to sell.
To find when the inventory reaches zero, set \( b(x) = 0 \):
\[
75 - 10x = 0
\]
Solving for \( x \):
\[
10x = 75 \\
x = 7.5
\]
Therefore, the relevant domain is \( 0 \leq x \leq 7.5 \).