posted by rosie .
Sketch the graph of F(x).
You are not serious, are you?
F(x) can be any function. You would have to tell us what it is.
We don't plot graphs here, anyway.
There are websites that do that for you, such as
It would the the function F(x) defined in a previous post:
The graph is a straight line between the origin and (4000,80000), and is a horizontal line beyond that.