Knowledge Check: Functions

The vertical line test is a visual method used to determine whether
a relation represented as a graph is a function. To apply the vertical line test, consider all of the vertical lines that could be drawn on the graph of a relation. If any of the vertical lines intersect the graph of the relation at more than one point, then the relation is not a function.

Is a graph a function?

Things that can be counted
Contains whole numbers only.
Graph contains dots
Examples: purchasing tickets, # of students, # of text messages, etc.

​​Discrete

Things that are measured
Contains whole numbers, decimals, and fractions
Graph contains a line
Examples: time, temperature, weight, distance, etc.

Continuous

Multiple Choice

Review graphs a and b.

Which graph is a function?

• Neither

• Both

• b

• a

Multiple Choice

Review graphs a and b.

Which graph is a NOT function?

• Neither

• Both

• b

• a

Multiple Choice

Are the graphs discrete or continuous?

• Discrete

• Continuous

• Neither

• Both

Open Ended

Review the graphs.

Which is a function and which is NOT a function. Explain your reasoning.

Open Ended

Are these graphs discrete or continuous?