Johnny throws a tennis ball as far as he can. We have the following function f(x) = -4x² + 8x + 7 expressing a function of t where x represents the number of seconds since the tennis ball left Johnny's hand and f(x) represents the height of the tennis ball in feet. a. Graph the function. b. Identify the y-intercept. c. Identify the vertex. d. The graph should not go outside of the first quadrant. Why? e. What do the x and y axis represent? f. What is the maximum height of the tennis ball? h. How many seconds does it take for the ball to hit the ground? i. After 1.5 seconds have passed, is the ball going up or down? g. How many seconds does it take for the ball to reach its maximum height? j. After 0.5 seconds have passed is the ball going up or down? k. After 1 second has passed, is the ball going up or down? 1. What interval is the ball going up? 16 15 14 13 12 11 10 9 8 7 6 5 4 m. What interval is the ball going down? 3 2 1 0 1 2 3 6 8 9 10 11 2/2 12 X​