# Function Notation - Revenue of sleeping bags

• Mar 23rd 2013, 07:45 AM
IvoryChan
Function Notation - Revenue of sleeping bags
The relationship between the selling price of a sleeping bag, s dollars, and the revenue at that selling price, r(s) dollars, is represented by the function r(s)=-10s2 + 1500s.
Evaluate, interpret and compare r(29.95), r(60.00), r(75.00), r(90.00), and r(130.00). (13 marks)

a) r(29.95) = 35,954.97

They made a revenue of \$35, 954.97.

b) r(60.00) = 54,000

They made a revenue of \$54, 000.

c) r(75.00) = 56, 250

They made a revenue of \$56, 250.

d) r(90.00) = 54, 000

They made a revenue of \$54, 000.

e) r(130.00) = 26,000

They made a revenue of \$26, 000.

The highest revenue to be made is from selling the sleeping bag at \$75.00 for a total revenue of \$56, 250.
The lowest revenue to be made is from selling the sleeping bag at \$130.00 for a total revenue of \$26, 000.

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As you can see, I have the answers (and I have my work shown on my actual sheet to hand in).
Basically, I'm asking if I'm supposed to be doing anything else to get the full 13 marks. The words "Evaluate, interpret, and compare" are pretty vague to me. Am I supposed to make like a table of values or a graph too?

Am I supposed to answer the question as to WHY the revenue is low if the selling price is at it's highest?
If that is the case, what am I supposed to say in context of the question other than because there is a negative on the -10s2.
• Mar 23rd 2013, 03:02 PM
Debsta
Re: Function Notation - Revenue of sleeping bags
I'd say you have evaluated and interpreted, but haven't yet compared. You need to look at what happens to the value of r as s increases. ie gets bigger and then gets smaller. A graph would be very helpful. You can then identify when r is greatest.