Foursquare provides a service that allows your friend to know your whereabouts by checking in . From march 2010 to march 2011 it experienced amazing growth. The function : F(x)=1/18x^2 - 1/12^x + 1/2
Evaluate F(3)?
Determine when foursquare had 4.25 million users ?
You did not define what x nor F(x) represent.
But that does not stop us from finding
F(3) = (1/18)(3)^2 -1/12^3 + 1/2
= (1/18)(9) - 1/1728 + 1/2
= 1/2 - 1/1728 + 1/2
= 1 1/1728 or 1729/1728 whatevers
(I have suspicions about the term 1/12^x , is it a typo ? )
4.25 users ? don't know which variable is defined as "users"