The function f(x) = 2.75x? - 36.9x +104.9 describes the united states trade balance with mexico in billions of dollars
for the period 1994-1998 (1994 corresponds to x = 4).
1. according to the function when was the u. s. deficit greatest (largest negative value)?
2. when was trade balanced (y = 0) for the period 1994-1998?
3. if the function continues to model u. s.-mexican trade, will trade be balanced again? when?