11.1 Relations and Functions

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11.1 Relations and Functions

• OBJ ? Determine the domain and range of a
  relation
• ? Determine whether a
  relation is a function

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• P276 What is the set of ordered pairs graphed
  below, starting with the two points on the
  left?
• ( 1, 2 ), (1, 1), (2, 1), (3, 2)

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• DEF ? Relation
• A set of ordered pairs
• ? Domain
• A set of x coordinates
• ? Range
• A set of y coordinates
• ? ? What is the domain?
• 1, 2, 3
• ? What is the range?
• 2, 1, 1, 2

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• P276 EX 1 What is the relation graphed below?
• HW 3 P278 (2-12e)
• ( 3, 2 ), (1, 3), (3, 2), (4, 1)
• ? What is the domain?
• 3, 1, 3, 4
• ? What is the range?
• 2, 1, 2, 3

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• DEF ? Function HW 3 P278 (2-12e)
• P277 Relation with no repetition in
  the domain
• EX 2 ? Is (-1,2), (2,2), (3,-1) a function?
• Yes
• ? Is (2,3), (3,4), (2,6) a
  function?
• No
• EX 3 ? Is the relation graphed below a
  function?
• HW 3 P278 (14-20e)
• Yes
• NOTE The open circle indicates the point is not
  a
• point of the graph.

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• ? ? What is the domain?
• ( 4, 4 or x 4 lt x 4
• ? What is the range?
• 0, 4 or y0 y 4
• TEST Vertical Line Test HW 3 P278 (14-20e)
• P277 If you can draw a vertical line
• through only 1 point, it is a
  function.
• EX 4 ? Which of the relations graphed below
• are functions?
• 1) No 2) Yes
  3) No