1 A.SSE.2: I can take a quadratic expression and identify different ways to rewrite it. A.CED.1: I can create equations and inequalities in one variable and use them to solve problems. A.APR.3: I can identify the ‘zeros’ of a quadratic function. --Solving a quadratic function is actually finding the place or places where the function crosses the x-axis. These x-intercepts are called solutions, roots, or zeros of the quadratic function. --One method used to solve a quadratic function is called factoring. --The Zero Product Property states that if (x+p)(x+q) = 0, then x+p = 0 or x + q = 0. Therefore, once we factor a quadratic and put the quadratic into intercept form, then we can set each factor equal to 0, and solve for x. This x value will be the solution to the quadratic equation. Solve each quadratic function. 1. x2 + 11x + 28=0 2. x2 + 11x + 24=0 3. s2 + 13s + 42=0 4. x2 10x + 21=0 5. x2 + 9x 18=0 6. w2 + 12w 35=0 7. 6x2 9=0 8. 16m2 + 8m=0 9. 2a2 + 22a + 60=0 10. 5x2 + 25x 70=0 11. 5x2 17x + 6=0 12. 3x2 + 10x + 8=0 13. n2 49=0 14. 2x2 50=0 2 15. The area of a rectangular field is x2 x 72 m2. The length of the field is x + 8 m. What is the width of the field in meters? 16. The product of two integers is w2 3w 40, where w is a whole number. Write expressions for each of the two integers in terms of w. 17. John is j years old. The product of his younger brother’s and older sister’s ages is j2 2j 15. How old are John’s brother and sister in terms of John’s age? Solve each equation by factoring. Check your answers. 18. x2 – 2x – 24 = 0 19. 3x2 = x + 4 20. x2 – 6x + 9 = 0 21. 3x2 + 45 = 24x Solve each equation using tables. Give each answer to at most two decimal places. 22. 5x2 + 7x – 6 = 0 23. x2 – 2x = 1 Solve each equation by graphing. Give each answer to at most two decimal places. 24. 10x2 = 4 – 3x 25. 3x2 + 2x = 2 26. A woman drops a front door key to her husband from their apartment window several stories above the ground. The function h = –16t2 + 64 gives the height h of the key in feet, t seconds after she releases it. a. How long does it take the key to reach the ground? b. What are the reasonable domain and range for the function h? 27. You use a rectangular piece of cardboard measuring 20 in. by 30 in. to construct a box. You cut squares with sides x in. from each corner of the piece of cardboard and then fold up the sides to form the bottom. a. Write a function A representing the area of the base of the box in terms of x. b. What is a reasonable domain for the function A? sc. Write an equation if the area of the base must be 416 in.2. d. Solve the equation in part (c) for values of x in the reasonable domain. e. What are the dimensions of the base of the box? 3 28. STEM: Physics: The function h = −16𝑡 2 + 1700, gives an object’s height ‘h’, in feet, at ‘t’ seconds. a. What does the constant 1700 tell you about the height of the object? b. What does the coefficient of 𝑡 2 tell you about the direction the object is moving? c. When will the object be 1000 feet above the ground? d. When will the object be 940 feet above the ground? e. What are the reasonable domain and range for the function ‘h’?