The graph shows , the number of bacteria (in thousands) in a lab culture hours after the start of an experiment.
Which choice is the value of ?
An expression like uses function notation: the number in parentheses is the input, and the function's value is the output. Find the input on the horizontal axis, then read the point's height on the vertical axis. The output is the height of the point at the given input. If that point is marked, you don't need Desmos or a formula.
Hints
- Hint 1
In function notation, the number inside the parentheses is the input. For , which axis shows the input measured in hours?
- Hint 2
A graph point is an ordered pair: its first coordinate gives the input, and its second coordinate gives the output. Find the marked point above . What height does it reach?
Step-by-step
Read the marked point
Step 1Locate the input
No Desmos needed. Read the marked point on the graph.
means the input is hours. Find on the horizontal -axis and look up to the marked point.
- Step 2
Read the output
The marked point is . In this ordered pair, the second coordinate is the output, so . Since the graph counts bacteria in thousands, that means thousand bacteria after hours. Choice C.