Warm-up (10-25-11)

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Warm-up (10-25-11)

• 1. Multiply with FOIL (2x 4)(6x 2)
• 2. Given y -2(x 4)2 5, then find
• Vertex Point?
• AOS?
• y-intercept?
• Opening Direction?
• Graph it?

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Chapter 4

• Section 4-1
• Graphing Quadratic Equations

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Objectives

• I can identify a, b, c from a quadratic equation
• I can graph Quadratic Functions manually with
  Data Table, including Axis of Symmetry
• I can describe the three types of solutions to a
  quadratic equation

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Quadratic Equation

• A quadratic equation is an equation that can be
  written in the format
• y ax2 bx c, where a ? 0
• ax2 is the quadratic term that makes it a
  quadratic

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Real World Applications
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Vocabulary versus Answer Format

• Solutions and Roots have the same answer format
• x or in braces
• x 3, 5 3, 5
• Zeros and x-intercepts have the same answer
  format as ordered pairs
• (xint , 0)
• (3, 0) and (5, 0)

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Axis of Symmetry

• The axis of symmetry can be found by the
  following equation

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y 3x2 - 2x - 1

• Find AOS?
• a 3, b -2, c -1
• AOS

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y -2x2 4x - 8

• Find AOS?
• a -2, b 4, c -8
• AOS

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Finding the Vertex Point

• If the AOS is x 1, then the Vertex Point is
  Vertex (1, ?)
• How can I find the y-value?
• PLUG the x-value back into the equation for all
  xs and solve for y

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y -2x2 4x - 8

• AOS x 1
• Now use this x-value to find the vertex point
• y -2(1)2 4(1) 8
• y -2 4 8
• y -6
• Vertex (1, -6)

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Putting it ALL together to GRAPH
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Example

• Lets graph y 2x2 4x 5
• So we need
• 1. AOS
• 2. Vertex Point
• 3. More points to graph

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Homework

• Worksheet 4-2