Calculas:

Derivatives

4. The world's growing population can be modelled by an exponential equation. If we assume the world's population was approximately 4 billion in the year 1975, then the population at a time t years after 1975 can be found by the equation P = 40019t. c. Estimate the world's population when you are 30 years old. d. At what rate is the population changing at this time? 5. The height of the tides at a certain spot in Nova Scotia can be found by the equation h(t) = 5sin (0.5t + 2) + 6, where t is the time in hours (using a 24-hour clock) and h is the height in metres. What is the rate of change of height at a time of 07:00 h