1 Solving Quadratic Equations 1Shaw 2008 February 16, 2010
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3 STANDARD FORM: QUADRATIC EQUATION Parabola: The graph of a Quadratic Equation 3Shaw 2008
4 Negative value for a: The Parabola opens DOWN For example What is the value for a? It’s a sad graph 4Shaw 2008
5 Positive value for a: The Parabola opens UP For example What is the value for a? It’s a happy graph! 5Shaw 2008
6 VERTEX Where would the Vertex be on these two graphs? 6Shaw 2008
7 VERTEX If a is positive: the vertex is the MINIMUM value of the function. If a is negative: the vertex is the MAXIMUM value of the function. The Vertex always lies on the LINE OF SYMMETRY Shaw 2008
8 EXAMPLE 1 What do we know: Does this graph open up or down? Does the vertex have a MAXIMUM or a MINIMUM value? 8Shaw 2008
9 EXAMPLE 2 Does the graph face up or down? Is the vertex a Max or Min? Shaw 2008
Solving Quadratic Equations When you are “solving” a quadratic equation you are finding the x-intercepts of the graph How many solutions will the equation have? Solve the following equation by graphing:
Solving Quadratic Equations Solve the following two equations algebraically What variable should we solve for?
Solving Quadratic Equations Solve the following equations algebraically
13 HOMEWORK # 14!!! Solving Quadratic Equations Worksheet #3-21 multiples of 3 #52, 53, 55 #24-45 multiples of 3, 44, 47 Shaw 2008