Identifying Functions

Front

What is a function?

Back

A function is a relation where every input (x-value) has exactly one output (y-value).

Tags

CCSS.8.F.A.1

Front

Which of the following is a function? {(9,5), (10,5), (9,-5), (10,-5)}

Back

Not a function, because the input 9 has two different outputs.

Tags

CCSS.8.F.A.1

Front

Which of the following is a function? {(3,4), (4,-3), (7,4), (3, 8)}

Back

Not a function, because the input 3 has two different outputs.

Tags

CCSS.8.F.A.1

Front

Which of the following is a function? {(6,-5), (7, -3), (8, -1), (9, 1)}

Back

This is a function, as all inputs have unique outputs.

Tags

CCSS.8.F.A.1

Front

Which of the following is a function? {(2, -2), (5, 9), (5, -7), (1, 4)}

Back

Not a function, because the input 5 has two different outputs.

Tags

CCSS.8.F.A.1

Front

What is the vertical line test?

Back

A method to determine if a graph represents a function; if a vertical line intersects the graph at more than one point, it is not a function.

Front

Is the graph of y = x^2 a function?

Back

Yes, it is a function because each x-value has one corresponding y-value.

Front

Is the graph of y = √x a function?

Back

Yes, it is a function because each x-value has one corresponding y-value.

Front

Is the graph of y = ±√x a function?

Back

No, it is not a function because each x-value has two corresponding y-values.

Front

What is the domain of a function?

Back

The set of all possible input values (x-values) for the function.