Question d3d3fb9c

The population P of a certain city y years after the last census is modeled by the equation below, where r is a constant and $P subscript 0$ is the population when $y equals 0$ .

$P equals, P subscript 0, times, open parenthesis, 1 plus r, close parenthesis, to the power y$

If during this time the population of the city decreases by a fixed percent each year, which of the following must be true?

Advanced Math - Nonlinear functions