Isabel’s competition,who sells books and no other products, charges a shipping fee of $1.99 per book plus a fixed fee of $3 for each order. Let x be the number of books purchased and f(x) be the price of shipping one order of books. Write a function that expresses f(x) and explain the value of f(x) for x =

Question

luisjimenez · Answer

for the function i get f(x)=1.99x+3 but how do i explain when x=0?

retireed · Answer

The easiest thing to do is to set a limit on your domain.  Your answer is obviously a linear function and you are concerned with the value at x equals zero.

Well, obviously x cannot go negative right.  It makes no sense to have negative orders.  So I content that a zero order also makes no sense, since you can't can't have a fixed charge for nothing.  I would make my function this.....

     f(x) = 1.99x + 3  for x>0

luisjimenez · Answer

how do i explain when x= 0 then?

luisjimenez · Answer

cause that's what it's asking but if 0 books are purchased than there shouldnt be fixed fee of $3

luisjimenez · Answer

do i just state that x cannot be 0?

retireed · Answer

$$x \ge 1$$    X cannot get to zero it is no allowed by the function I defined