Question

for the period 1990-2003, the amount of biscuits and pasta y(in thousands of tons) imported to the united states can be modeled by the function: y=1.36x^2+27.8x+77
how many tons obiscuits and pasta were imported to the states in 1999?
in which year was the maximum imported?
what was the maximum amount imported?

Answer 1

You did not define x
I assume x represents the number of years since 1990

So for 1999 , x = 9
sub in 9 and evaluate

YOur equation represents a parabola,
find the vertex ...

since the parabola opens up, there will be a minimum and a quick mental calculation will show that to be a negative x
----> must have happened before 1990

Since all the terms are positive, the value of y will increase as x increases, so the max will be in 2003
or when x = 13
just evaluate for x = 13