What is estimated population of the city in 2010?

Question

The quadratic function f(x)=45x^2+350x+1590 models the population of a city where x represents the number of years since 2005 and f(x) is the population of the city in thousands of people.

 

A)2,215,000

B)1,095,000

C)2,070,000

D)590,000

Answer 1

2010 is 5 years since 2005, so just plug x = 5 into f(x).

 

f(5) = 45(5²) + 350(5) + 1590 = 4465 thousands of people in 2010