Thinking Mathematically

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Thinking Mathematically

• Chapter 7
• 7.1 Graphing and Functions

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• A function is a relation between 2 sets X and Y
  such that every element in the set X is assigned
  a unique element in the set Y.
• We write f(x) y for x in X and y in Y.
• CAUTION f(x) doesnt mean f multiplied by x.
• Functions are often described by formulas
• Example

find f(2) and f(-5).
For the above function, find
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Ordered pairs

• We can display a function by showing its graph in
  the rectangular (Cartesian) coordinate system.
• The graph of an equation is the collection of all
  points (x,y) that make the equation true when
  you substitute the first value in for x and the
  second value in for y in the equation.
• Example The ordered pair (1,3) satisfies the
  equation yx2 because 3 12 is a true
  statement.
• The 1st coordinate of an ordered pair gives the
  horizontal position of the point. The 2nd
  coordinate gives its vertical position.

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Graphing Functions

• Example Fill in the following table and use it
  to graph the function.