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Explore the fundamental concepts of quadratic equations through examples and step-by-step instructions. This lesson covers how to find the vertex of a quadratic function and explains the process of solving quadratic equations by factoring. Learn the importance of identifying coefficients a, b, and c, and how to apply these concepts practically to solve equations like x² + 4x - 12 = 0. Gain confidence in algebra by mastering the techniques of finding x-intercepts and factoring polynomials effectively.
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10 January 2011 Algebra 2
Bellringer • Find the vertex: f(x)=x2 + 10x – 5 • What are factors?
Vocabulary • Vertex • Zero • X-intercept • Parabola
Solving Quadratics by Factoring 1/10 If the quadratic equation is already factored, set each set of parentheses equal to zero, then solve for x (x + 5)(x – 2) = 0 Already Factored
Solving Quadratics by Factoring 1/10 If the quadratic equation is already factored, set each set of parentheses equal to zero, then solve for x (x + 5)(x – 2) = 0 x + 5 = 0 x – 2 = 0 Already Factored
Solving Quadratics by Factoring 1/10 If the quadratic equation is already factored, set each set of parentheses equal to zero, then solve for x (x + 5)(x – 2) = 0 x + 5 = 0 x – 2 = 0 - 5 - 5 + 2 + 2 Already Factored
Solving Quadratics by Factoring 1/10 If the quadratic equation is already factored, set each set of parentheses equal to zero, then solve for x (x + 5)(x – 2) = 0 x + 5 = 0 x – 2 = 0 - 5 - 5 + 2 + 2 x = -5 x = 2 Already Factored
Solving Quadratics by Factoring 1/10 If the quadratic equation is not factored, -Identify a,b,c x2 + 4x - 12= 0 Factor a Quadratic
Solving Quadratics by Factoring 1/10 If the quadratic equation is not factored, -Identify a,b,c x2 + 4x - 12= 0 a b c Factor a Quadratic
Solving Quadratics by Factoring 1/10 If the quadratic equation is not factored, -Identify a,b,c x2 + 4x - 12= 0 a b c a = 1 b = 4 c = -12 Factor a Quadratic
Solving Quadratics by Factoring 1/10 If the quadratic equation is not factored, -Multiply a and c x2 + 4x - 12= 0 a = 1 c = -12 ac = -12 Factor a Quadratic
Solving Quadratics by Factoring 1/10 If the quadratic equation is not factored, -Make a chart listing the factors of ac ac = -12 b = 4 Factor a Quadratic
Solving Quadratics by Factoring 1/10 If the quadratic equation is not factored, -Add the a and c columns ac = -12 b = 4 Factor a Quadratic
Solving Quadratics by Factoring 1/10 If the quadratic equation is not factored, -Add the a and c columns ac = -12 b = 4 Since b = 4, and 6 + -2 = 4, our factors are 6,-2. Factor a Quadratic
Solving Quadratics by Factoring 1/10 x2 + 4x - 12= 0 Factors: 6,-2 Factor a Quadratic
Solving Quadratics by Factoring 1/10 x2 + 4x - 12= 0 Factors: 6,-2 Factored Form: (x + 6)(x – 2) = 0 Factor a Quadratic
Solving Quadratics by Factoring 1/10 x2 + 4x - 12= 0 Factors: 6,-2 Factored Form: (x + 6)(x – 2) = 0 Solve: x + 6 = 0 x – 2 = 0 Factor a Quadratic
Solving Quadratics by Factoring 1/10 x2 + 4x - 12= 0 Factors: 6,-2 Factored Form: (x + 6)(x – 2) = 0 Solve: x + 6 = 0 x – 2 = 0 Final Answers: x = -6, 2 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2 -Identify a,b,c x2 + 5x + 6= 0 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2 -Identify a,b,c x2 + 5x + 6= 0 a b c Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2 -Identify a,b,c x2 + 5x + 6= 0 a b c a = 1 b = 5 c = 6 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2: Multiply ac, and make a table ac = 6 b = 5 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2: Multiply ac, and make a table ac = 6 b = 5 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2: Multiply ac, and make a table ac = 6 b = 5 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2: Multiply ac, and make a table ac = 6 b = 5 factors: 2,3 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2 x2 + 5x + 6= 0 factors: 2,3 Factored Form: (x + 2)(x + 3) = 0 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2 x2 + 5x + 6= 0 factors: 2,3 Factored Form: (x + 2)(x + 3) = 0 Solve: x + 2 = 0 x + 3 = 0 Factor a Quadratic
Solving Quadratics by Factoring 1/10 Example 2 x2 + 5x + 6= 0 factors: 2,3 Factored Form: (x + 2)(x + 3) = 0 Solve: x + 2 = 0 x + 3 = 0 Final Answers: x = -2, -3 Factor a Quadratic