Math CentralQuandaries & Queries


Question from jess, a student:

Let t^2 represent t-squared. The population of a Canadian City is modelled by: f(t) = 12t^2 + 800t + 40,000, where t is the time in years. When t= 0, the year is 2007.
a) According to the model, what will the population be in 2010?
B) In what year is the population predicted to be 300,000?

Hi Jess,

If t = 0 is 2007 then t = 1 is 2008, t = 2 is 2009 and t = 3 is 2010. Thus in your expression

f(t) = 12t2 + 800t + 40,000

substitute t = 3 to obtain the population that the model predicts for 2010.

For part b) you want t when 12t2 + 800t + 40,000 = 300,000. You will need to use the quadratic formula to solve for t.


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS