Domain and Range of a Function

Domain and Range

By Jason Dunn

D = {-3, -1, 1, 4, 5}​

Order doesn't actually matter, but often you'll see least to greatest.

Domain is the set of X values

R = {-5, 0, 2, 6}

​

Don't repeat the 2​

​

Range is the set of Y values

Open Ended

What is the domain of this chart of values?

Domain (X) = {-1, 0, 1, 2, 3}

​

Range (Y) = {1, 2, 3}​

​

​Can't remember which is which? D and R are alphabetical order and so are X and Y.

"Discrete" Function is scattered points​

​

Multiple Choice

Which of these sets is the RANGE of the graph?

• {0, 6, 12, 18}

• {-2, 0, 2, 4}

• {-2, 2, 4}

• {6, 12, 18}

Multiple Choice

Which number is not an element of the domain?

• 2

• 1

• 0

• 6

Fill in the Blank

What is the domain when the range is 3?

R: {-4 < y < 0}

​Graph goes as low as -4 and as high as 0

"Continuous" Graph

​

D: {-3 < x < 1}

​Graph goes as far left as -3, and as far right as 1

​

Multiple Choice

What is the domain of this graph?

• {-2 < x < 4}

• {-5 < x < 4}

• {-4, 0, -2}

• {-4 < x < 2}

Multiple Choice

Which number is outside the domain for this zig-zag shaped graph?

• -3

• 2

• 0

• 4

Open Ended

What is the range of this circle?

Some graphs go forever in a direction (just one inequality sign)

Multiple Choice

What is the domain of this graph?

• All Real Numbers

• x > -2

• x < 6

• -2 < x < 6

Domain is "all real numbers"

​

It looks like it goes full vertical, but it doesn't. Diagonal forever!​

​

Range is "everything above 0" so {y > 0}

Memorize

Multiple Choice

Parabolas go up forever. What is the range?

• y > -2

• y > 0

• y < 5

• y < 2

Multiple Choice

What is the range of this graph?

• y < 3

• y > -3

• y > 0

• All Real Numbers