Graphing Quadratic Functions A quadratic function is an equation of the form: y = ax 2 + bx + c.
Lesson 10-1 Graphing Quadratic Equations. Definitions Quadratic Function - can be written in the...
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Transcript of Lesson 10-1 Graphing Quadratic Equations. Definitions Quadratic Function - can be written in the...
Lesson 10-1
Graphing Quadratic Equations
Definitions
• Quadratic Function - can be written in the form of y = ax2 + bx + c, where a 0.
Parabola - The graph of a quadratic function is a parabola.
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Parabola
positive
Negative
Equation of the Axis of Symmetry
• The equation of the axis of symmetry for the graph of y = ax2 + bx + c, where c 0, is
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x =−b
2a
6 Steps to Graphing Quadratic Equations
1. Solve for line of symmetry using
2. Plug x value into original equation to find vertex (x,y).
3. Define vertex as a minimum or a maximum.
4. Find value of three numbers above and below line of symmetry value.
5. Plot points you have found.
6. Draw graph.
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x =−b
2a
Use a table of values to graph y = x2 - x - 2.
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x y
Use a table of values to graph y = -2x2 + 2x + 4.
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x y
Consider the graph of y = -2x2 -8x -2.
1. Write an equation of the axis of symmetry.
2. Find the coordinates of the vertex.
3. Identify the vertex as a maximum or a minimum.
4. Graph.
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x y
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x y