6. The x-coordinate of the vertex is given by X = - -b. Use this information to determine 8. How many x-intercepts does each function have? Explain how you know. Then, the vertex of each quadratic function. determine whether each intercept is a) y = x2 + 6x + 2 positive, negative, or zero. b) y = 3x2 - 12x + 5 a) a quadratic function with an axis of c) y = -x2 + 8x - 11 symmetry of x = 0 and a maximum 7. A siksik, an Arctic ground squirrel, value of 8 jumps from a rock, travels through the b) a quadratic function with a vertex at air, and then lands on the tundra. The (3, 1), passing through the point (1, -3) graph shows the height of its jump as a c) a quadratic function with a range of function of time. Use the graph to answer y21 each of the following, and identify which d) a quadratic function with a y-intercept characteristic(s) of the graph you used in of 0 and an axis of symmetry of x = -1 each case. 9. Consider the function f(x) = -16x2 + 64x + 4. 30 a) Determine the domain and range of the function. Height (cm) 20 b) Suppose this function represents the 10 height, in feet, of a football kicked into the air as a function of time, in seconds. 0 13 What are the domain and range in Time ($) this case? a) What is the height of the rock that the c) Explain why the domain and range are siksik jumped from? different in parts a) and b). b) What is the maximum height of the siksik? When did it reach that height? Apply 10. Sketch the graph of a quadratic function c) How long was the siksik in the air? that has the characteristics described in d) What are the domain and range in this each part. Label the coordinates of three situation? points that you know are on the curve. e) Would this type of a) x-intercepts at -1 and 3 and a range of motion be possible y 2 - 4 for a siksik in real b) one of its x-intercepts at -5 and vertex life? Use your at (-3, -4) answers to parts c) axis of symmetry of x = 1, minimum a) to d) to value of 2, and passing through (-1, 6) explain why d) vertex at (2, 5) and y-intercept of 1 or why not