472 Chapter 8Graphing Quadratic FunctionsUsing Intercept Form (pp. 449–458)8.5Use zeros to graph h(x) x2 7x + 6.The function is in standard form. The parabola opens up (a> 0), and the y-intercept is 6. So, plot (0, 6).The polynomial that de nes the function is factorable. So, write the function in intercept form and identify the zeros. h(x) x2 7x + 6 Write the function. (x 6)(x 1) Factor the trinomial.The zeros of the function are 1 and 6. So, plot (1, 0) and (6, 0). Draw a parabola through the points.Graph the quadratic function. Label the vertex, axis of symmetry, and x-intercepts. Describe the domain and range of the function. 22. y (x 4)(x + 2) 23. f (x) 3(x + 3)(x + 1) 24. y x2 8x + 15Use zeros to graph the function. 25. y 2x2 + 6x + 8 26. f (x) x2 + x 2 27. f (x) 2x3 18x 28. Write a quadratic function in standard form whose graph passes through (4, 0) and (6, 0).Comparing Linear, Exponential, and Quadratic Functions (pp. 459−468)8.6Tell whether the data represent a linear, an exponential, or a quadratic function. a. (4, 1), (3, 2), (2, 3) (1, 2), (0, 1)32x42yb. x10123y1581613+ 1 7 7 7 7+ 1+ 1+ 1x10123y1581613 The points appear to represent a quadratic function.The rst differences are constant. So, the table represents a linear function. 29. Tell whether the table of values represents a linear,an exponential, or a quadratic function. Then write the function. 30. The balance y (in dollars) of your savings account after t years is represented by y 200(1.1)t. The beginning balance of your friend’s account is $250, and the balance increases by $20 each year. (a)Compare the account balances by calculating and interpreting the average rates of change from t 2 to t 7. (b) Predict which account will have a greater balance after 10 years. Explain. x10123y512128328224xy484h(x) x2 7x + 6