The population of a town is modelled by P=-0.1x^2+1.2x+4.4 where x is the number of years since the year 2000, and �y is the population in thousands.

Question

a) In the year 2005, what is the population?

I used the equation, put x=5 and I got 7900 as the population.

b) In the year 1999, what is the population?

I used the equation, put x=-1 and I got 3100 as the population.

c) When was the population of the town the greatest? What was the
greatest population?

I used the vertex, (6,8). So in 2006 the greatest population was 8000 people.

d) The town has really become a terrible place to live.Predict when all the residents will leave the town.

How would I do this? Please help

Answer 1

you want P(x) = 0
Just use the quadratic formula to get x = 14.9

so, by the end of 2014 P will have dropped to zero.