Do Now:

1
Do Now

• Determine if the following relations are
  functions. For part (b) only, state the domain
  and the range.

NOT A FUNC-TION

1. (-2,5), (1.25,8), (1,4), (11,0), (1,6)

4 9 17
-6 4 8
NOT A FUNCTION
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Aim What notation do we use for functions?
Homework Red Book Pg 504 7-21 odd, 29
3
Remember

• A relation is any set of ordered points
• In mathematics, we use equations to talk about
  many ordered points at once.

gtSo, all equations are relations
gtMany equations are functions (and these are
the ones that we focus on)
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Examples
These are not functions
These are functions
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To show that equations are functions
We change y to f(x)
Pronounced f of x
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Benefits
Clearly shows how to find the output (the
corresponding element of the range
Clearly shows your input (an element of the
domain)
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Using Function Notation
Two of the elements in the domain of f(x) x5
are 1 and 4. Find the corresponding range
elements.
f(x) x5
f(1) (1)5 6
So 1 is related to 6
f(4) (4)5 9
So 4 is related to 9
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Sample Test Question

• If ,
• Then find f(x1).

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Sample Test Question
What this is really asking -Find the values of
x that will NOT relate to an element of the
range, and dont include them in the domain.
(If you included these values, this would not be
a function!)