After being thrown from the top of a tall building, a projectile follows the path (x, y) = (60t, 784 - 16t ^ 2) where x and y are in feet and t is in seconds. Notice that x and y are both defined as a function of t. This situation is called parametric equation and t is called the parameter. The Sun is directly overhead, so that the projectile casts a moving shadow on the ground on the ground beneath it, as shown in the figure. When t = 1