Sales of SUVs sport utility vehicles in the United States in

Sales of SUVs (sport utility vehicles) in the United States (in millions) for the years 1990-1999 can be modeled by the quadratic function shown below.

f(x)= 0.016x^2 + 0.124x + 0.787

Here x = 0 represents 1990, x =1 represents 1991, and so on. Us the model to approximate sales in 1997

Sales in 1997 were appriximately ____ million SUVs

Solution

f(x)= 0.016x^2 + 0.124x + 0.787 --------------------(1)

x = 0 represents 1990

x = 1 represents 1991

similarly, x = 7 represents 1997 --------------------(2)

substituting (2) in (1)

f(x = 7) = 0.016 (7^2) + 0.124 (7) + 0.787

= 0.784 + 0.868 + 0.787

= 2.439

Sales in 1997 were appriximately 2,439,000 SUVs