# Algebra2

posted by .

The function f(t)=100,000/1+5000e^(-t) represents the population of an endangered species bird t years after they were introduced to a non-threatening habitat.

a.In what year will there be 70,000 birds?

b.How many birds were intially introduced to the habitat?

c.How many birds are expected in the habitat eleven years after the introduction?

I'm thinking y=y0e^(-t)as the formula.
Looking for advice on set up of calculation, not necessarily answers to all.

• Algebra2 -

a) So, 70000 = 10000/(1 + 5000e^(-t)
1+5000e^-t = 10/7
5000e^-t = 10/7 - 1 = 3/7
e^-t = 3/35000 = .000085714
ln both sides
-t = ln .000085714
-t = -9.36
t = 9.36 years

b) when t=0
f(0) = 100000(1+ e^0) = 100000/2 = 50000

c) plug in t=11, you do the button-pushing

## Similar Questions

1. ### Biology

What are 2 reasons for a species to become threatened or endangered?
2. ### diffeq

Let P(t) represent the population of a non-native species introduced to a new area for the purposes of harvesting. Suppose we intially introduce P0 = 100 indicidcuals and suppose the population grows exponentially with growth-rate …
3. ### biology

1.can introduced species strengthen the immune system of the native species 2. can an introduced species change thec composition of the natural habitat so it is unsuitable for the native species
4. ### evolutionary machanism - BIOLOGY

A flock of migrating birds is blown off course by a storm and carried towards a small island that has no birds. Only three of the birds survive the storm and make it to the island. They start to reproduce and, after several years there …
5. ### Science

Jessica and David spotted birds at the neighborhood park where they had a bird feeder set up. Why are the birds a consumer in this habitat?
6. ### Pre Calculus

The logistic growth function P(t)= 160/ 1 + 9e^-0.165t describes the population of the endangered species of elk "t" years after they were introduced into the habitat. a. How many elk were initially introduced into the habitat?
7. ### Math

In a favorable habitat and without natural predators, a population of reindeer is introduced to an island preserve. The reindeer is introduced, F(t), t as the year after their introduction is modeled by the poly function F(x)=-0.125t^5+3.125+4000. …
8. ### Math

Waddell Mountains have a species of bird that hatches two new birds each week. Currently, there are 7 birds. Write a function representing this growth?
9. ### Pre-Calculus

A population of 20 rabbits is introduced to a small island. The population increase at a rate of 60% per year. (A) Find a function of F(t) that represents the number of rabbits on the island after t years. (B) Suppose 100 rabbits were …
10. ### Pre algebra

* There are 1,000 of an endangered species of bird left. If the population drops by 50% each year, how many years until there are only 1% of the current total left?

More Similar Questions