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Bellringer. Solve the equation and graph the related function. a. What is the maximum number of x-intercepts possible? b. How many x-intercepts are there and where are they? HINT: The factored form of the polynomial is: (x+2)³(x-3)².
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Bellringer Solve the equation and graph the related function. a. What is the maximum number of x-intercepts possible? b. How many x-intercepts are there and where are they? HINT: The factored form of the polynomial is: (x+2)³(x-3)²
4-2A Graphing Calculators: Graphing Quadratic Functions • Solve 0 = -5x² + 3.27x + 19.11 • Do #2-10 evens on page 186
4-2 Quadratic Equations and Inequalities • Solve Quadratic Equations by: • Factoring • Graphing • Use the quadratic formula • Completing the square
Solve • -10x² - 50x + 1500 = 0 • 4x² - 8x + 3 = 0 • x² - 6x + 13 = 0
Discriminants Discriminant Nature of the Roots b² - 4ac > 0 two distinct real roots b² - 4ac = 0 exactly one real root b² - 4ac < 0 no real roots (imaginary)
Complex Conjugates Theorem • If a + bi is a root of a polynomial equation, then a – bi is also a root of the equation.
Graph: y > x² + 8x – 20Without a calculator! • Find the x-intercepts using by factoring or using the quadratic formula. • Find the y-intercept (substitute 0 in for x). • Find the vertex: Find the first derivative of the equation, solve for x, and then substitute that value into the original equation for x to get the y-coordinate of the vertex. • Graph! • Finally - Shade
Example • Solve the equation by completing the square: 2x² + 11x – 21 = 0.