[填空题]
The number of fish in a lake after t weeks is modelfnvfgu9vi3q+jvtj,w(- lz 9; led bhj /khk:9eqv4(hej*6bu7z x f;3 hbzcy
$F(t)=\frac{4500}{1+4 e^{-0.5 t}}, t \geq 0$
1.Find the initial fish population,The number is .
2.Find the percentage increase of the population after 1 week, the population increase is .
3.Find the limit of the population size.that the population size stabilizes at fish, this size is known as the carrying capacity.
4.Find F′(t), and determine if the population is increasing or decreasing over time.
5.Find the rate at which the population is increasing after 8 weeks.F'(8)≈ .
