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2.4 Graphs of Functions. The graph of a function is the graph of its ordered pairs. Graphing a Function by Plotting Points. Steps for Graphing an Equation Using a Graphing Utility. Steps for Graphing an Equation Using a Graphing Utility. Steps for Graphing an Equation Using a Graphing Utility.
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2.4 Graphs of Functions The graph of a function is the graph of its ordered pairs.
Obtaining Information From Graphs You can obtain information about a function from its graph. At the right or left of a graph, you will find closed dots, open dots, or arrows. • An arrow indicates that the graph extends indefinitely in the direction in which the arrow points.
Obtaining Information From Graphs • A closed dot indicates that the graph does not extend beyond this point and the point belongs to the graph. • An open dot indicates that the graph does not extend beyond this point and the point does not belong to the graph.
The Vertical Line Test If any vertical line intersects a graph in more than one point, the graph does not define y as a function of x.
Increasing Function A function is increasing on an interval if for any x1 and x2 in the interval, where x1<x2, then f(x1)<f(x2).
Decreasing Function A function is Decreasing on an interval if for any x1 and x2 in the interval, where x1<x2, then f(x1)>f(x2).
Constant Function A function is constant on an interval if for any x1 and x2 in the interval, where x1<x2, then f(x1)=f(x2).
Ex 4: Intervals on Which a Function Increases, Decreases, or Is Constant
Graphs of Common Functions Use a graphing utility to verify the following six graphs.
Constant Function • Domain: • Range: the single number • Constant on • Even function