A farmer has a collapsable grain bag which can expand both vertically and horizontally as he
needs it to. He wants to find a function to
represent how much grain he can put in bag
based on how much he has expanded it. When
the bag is laying flat on the ground the area can
be represented by the function f(x) = 3x2 + 1
and as the bag is raised up the height can be
represented by the function g(x) = x+ 5.
In terms of x, how much grain can the bag
hold?