WARM UP Use f(x) = 3x2 4x

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WARM UPUse f(x) 3x2 4x 6 to evaluate
the following.1. f(2)2. f(-4)3. f(0)
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Math II
UNIT QUESTION What is a quadratic
function? Standard MM2A3, MM2A4 Todays
Question How do you graph quadratic functions in
standard form? Standard MM2A4.a.
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Notes-Graphing Quadratic Equations 3.1
Steps to graph quadratic equations
2. Identify the values of a, b, and c.
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Steps to graph quadratic equations (cont.)
4. Find your vertex (substitute your axis of
symmetry back into the original equation and
solve for y).
5. Construct a table of values for x and y.
Choose values of x, two above and two
below your x value in the vertex.
6. Plot the points and connect them with a
U-shaped curve.
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Graph opens up or opens down?
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OPENS DOWN
a -1 b 2 c -1
x -(x)22x-1 y (x, y)





?
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Tell whether the graph opens up or down. Graph
each using a T-chart. Find the axis of symmetry
? vertex ?. Use a dotted line to graph the
axis of symmetry.
OPENS UP
a 1 b -6 c 5
x x2- 6x 5 y (x, y)





?
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OPENS DOWN
a -1 b -2 c 3
x -(x)2- 2x3 y (x, y)





?
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OPENS DOWN
a 1 b 2 c -6
x (x)2 2x-6 y (x, y)





?
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OPENS UP
a 1 b 8 c 13
x (x)28x13 y (x, y)





?
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Converting to Vertex Form from Standard Form

• Find the vertex point, (h, k)
• a will be the a from the standard form equation.
• 3. Substitute into y a (x-h)2 k

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Converting to Vertex Form from Standard Form

1. Convert y 2x2 4x 5
2. Convert y -x2 2x 1

Vertex (1, 3) Standard form y 2(x-1)2 3
Vertex (-1, 2) Standard form y -(x1)2 2
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Homework
Pg. 59 23-33 odd