posted by Alex .
A population of animals oscillates annually from a low of 1300 on January 1st to a high of 2200 on July 1st, and back to a low of 1300 on the following January. Assume that the population is well-approximated by a sine or a cosine function.
a. Find a formula for the population, P, as a function of time, t. Let t represent the number of months after January 1st. Find the amplitude, period and midline.