Lesson 5.1~~Parabolas
Objective: To be able to identify and graph the parent function known as the parabola.
What does this look like when graphed?
y = 2x + 1
y=5
y = 2x3 - 5
y = x2 - 2x
y = x+1 - 4
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Lesson 5.1~~Parabolas
Objective: To be able to identify and graph the parent function known as the parabola.
There are several ways to graph an equation...
1. Using a T-chart
2. Using a graphing utility.
3. Using graphing shortcuts.
You have used T-charts on several different occasions. We are
going to review T-charts again and look at some graphing shortcuts
which you may have discovered in your graphing assignment.
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Graph y = x2 + 3x - 4
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Graph y = (x - 2)2 +3
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Graph y = -(x + 1)2 + 2
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Graph y = -x2 +2
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What did you notice about the examples?
Vertex-----highest or lowest point of the parabola
Shortcut to get the vertex from the parabola's form:
y = a(x - h)2 + k
Vertex is ______________
Direction the parabola opens is determined from ______. If ______ is
____________ then the parabola will open up. If ______ is ____________
then the parabola will open down.
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If the equations are in the form y = a(x - h)2 + k, then you are able to
determine the vertex and the direction the parabola opens.
Examples:
1. y = 3(x - 2)2 + 1
V(____, ____)
up or down
2. y = (x + 1)2 + 4
V(____, ____)
up or down
3. y = -2(x - 3)2 + 1
V(____, ____)
up or down
4. y = -(x + 2)2 - 4
V(____, ____)
up or down
5. y = x2 - 2
V(____, ____)
up or down
6. y = - x2 + 3
V(____, ____)
up or down
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Now you are to SKETCH the graph of the parabola.
1. y = 3(x - 2)2 + 1
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SKETCH the graph of the parabola.
2. y = (x + 1)2 + 4
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