Question

Help?!?!

The table below represents the amount of money Cathy has in her money box as a function of time

Time Money
(month) ($)
x y
0 400
1 320
2 240
3 160

Part A: What is the y-intercept of the function and what does this tell you about the table?

Part B: What is the average rate of change of the function represented by the table between x = 1 to x = 3 months and what does the average rate represent?

Part C: What is the domain of the function represented by the table if Cathy does not put any money into the box

Answer 1

@hero @hoblos @satellite73

Answer 2

@RosieF, have you figured out part A yet?

Answer 3

I think that it's 400 and it represents that she already had $400. Is that right @Hero

Answer 4

Sounds like a great start :)

Answer 5

What about part B?

Answer 6

Hint: Average rate of change is a description for slope

Answer 7

Average rate of change
\[m = \frac{y_2 - y_1}{x_2 - x_1}\]

Answer 8

Would it be -80?

Answer 9

That appears to be correct. And what does -80 mean in this case?

Answer 10

she spends $80 each month?

Answer 11

Nice description

Answer 12

Okay :) so what about part C?

Answer 13

would that be 1,2,3?

Answer 14

Basically, what they want you to do is provide a "description" for the domain

Answer 15

what does that mean?

Answer 16

A description for the set of numbers that represent the input, x.

Answer 17

based on the given scenario

Answer 18

What does "x" represent?

Answer 19

the month?

Answer 20

You could say something like x represents "the number of months Cathy has money stashed in her box".

Answer 21

I still don't get what I'm supposed to use as my answer.

Answer 22

A description for the "domain" in words. Try to understand what x represents.

Answer 23

Oh! ok I get it. :)

Answer 24

Thanks :)