Question

Use of the internet in a country is given by the function f(x)=0.485x^2-1.694x+0.315, where the output is in millions of users. In this formula x=6 corresponds to 1996, x=7 corresponds to 1997, and so on until x=20 corresponds to 2010. Estimate when the number of internet users in the country reached 32 million. Please help!