A toy rocket is launched into the air from a building. The height, h, of the rocket in metres above the ground can be modelled by the following function where time, t, is in seconds: Show all your work. () = −. 20 10.2 a) Determine the average rate of change of the height of the rocket from 1 to 3 seconds. b) Determinetheinstantaneousrateofchangeoftheheightofthebaseballatthree(3)seconds.