©Evergreen Public Schools What is a Function Teacher Notes Notes: Today students will create their understanding of a function: “In a function each input has only one output”. We will not use independent and dependent variables. 9/16/2011

©Evergreen Public Schools Practice Target Practice 6: Attend to precision. [Students] try to use clear definitions in discussion with others and in their own reasoning.

©Evergreen Public Schools Learning Target Connecting Patterns & Functions Target Do you remember what a function is? F-IFa I can understand the concept of a function and use function notation. Determine whether a table, equation, ordered pairs or a situation is a function. F-IF.1F-IF.1

©Evergreen Public Schools What does the word “function” mean. Can you define it? Can you use it in a sentence? Can you give an example?

©Evergreen Public Schools ExploreExplore

Today we will learn the definition of a function in algebra. Use the following examples to develop your own definition of the word function in algebra. ©Evergreen Public Schools

7 What do you notice? What do you think a function is? This table is a function. InputOutput This table is a not function. InputOutput

©Evergreen Public Schools What do you notice? What do you think a function is? This table is a function. InputOutput This table is a not function. InputOutput

©Evergreen Public Schools What do you notice? What do you think a function is? This table is a function. InputOutput This table is a not function. InputOutput

©Evergreen Public Schools What do you think a function is?

©Evergreen Public Schools Is this table of the L(x) pattern a function? Defend your answer. InputOutput

©Evergreen Public Schools Is this table a function? Defend your answer. InputOutput

©Evergreen Public Schools What do you notice? What do you think a function is? This graph is a function. This graph is a not function.

©Evergreen Public Schools Advance to see the last slide repeated.

©Evergreen Public Schools What do you notice? What do you think a function is? This graph is a function. This graph is a not function.

©Evergreen Public Schools What do you notice? What do you think a function is? This graph is a function. This graph is a not function.

©Evergreen Public Schools What do you think a function is?

©Evergreen Public Schools Is this graph a function? Defend your answer.

©Evergreen Public Schools Is this graph a function? Defend your answer.

©Evergreen Public Schools Here is a way to test if a graph is a function. The Vertical Line Test. Pass a vertical line over the graph. If the vertical line touches the graph only once, then the graph is a function. The graph is a function.

©Evergreen Public Schools Here is a way to test if a graph is a function. The Vertical Line Test. Pass a vertical line over the graph. If the vertical line touches the graph more than once, then the graph is not a function. The graph is not a function.  x x

©Evergreen Public Schools Why does the Vertical Line Test work? Use what you know about functions and tables to help you answer this question.

©Evergreen Public Schools What do you think a function is? It’s the same for a table and a graph.

©Evergreen Public Schools Is this graph of the k ( x ) pattern a function?

©Evergreen Public Schools Is this graph a function? Defend your answer.

©Evergreen Public Schools Is this graph a function? Defend your answer.

©Evergreen Public Schools Is this situation a function? Defend your answer. The year a person was born and the first year they can get a driver’s license.

©Evergreen Public Schools Is this situation a function? Defend your answer. The forecasted high temperature of a day and the low temperature of the same day. Click link to see forecasted our high and low temperatures.temperatures

Placemat ©Evergreen Public Schools What is a function? Name 1 Name 2 Name 3 Name 4

©Evergreen Public Schools Team Practice

©Evergreen Public Schools Debrief Quick Write… Describe your way of deciding if a graph, table or situation is a function.

©Evergreen Public Schools Learning Target Did you hit the target? F-IFa I can understand the concept of a function and use function notation. Rate your understanding of the target from 1 to 5. 5 is a bullseye!

©Evergreen Public Schools Practice

©Evergreen Public Schools Ticket Out InputOutput Is the table a function? Defend your answer.