Question

can anyone help me out on this question? ^_^
I got the inverse of the graph,... but I'm not sure how to plug in the rest
http://imgur.com/tOY12vM

Answer 1

\[f^{-1}(40)=x \implies f(x)=40 \\ \text{ look at the graph given and find for what } x \text{ you have the } \\ \text{ corresponding } y \text{ value is } 40\]

Answer 2

so basically my answer would be 10,000 ? (because the quantity sold are in thousands)

Answer 3

well you didn't exactly look for what I asked...
You found at x=40 then y=10 thousand

Answer 4

I was asking for what x you have y=40 thousand

Answer 5

find on the y-axis 40

Answer 6

you should see a dot moving your finger horizontally from the y-axis at 4-

Answer 7

at 40*

Answer 8

then move your finger vertically when you reach that dot
(down vertically until you get to the x-axis)

Answer 9

you should find the x for which y is 40

Answer 10

Ofcourse, but on the inverse graph isnt it (10,40

Answer 11

On the f(x) graph it's 20 (or 20,000?) then right?

Answer 12

perfect (20,40) is on f
so (40,20) is on f inverse
\[f(20)=40 \implies f^{-1}(40)=20\]

Answer 13

well 20 is no in thousand s

Answer 14

Oh, i see...

Answer 15

f(20)=40
says 20 things sold and the what is 40 thousand dollars

Answer 16

didn't read the whole question so you can make a better interpretation by reading of course :p

Answer 17

f^(-1)(40)=20 says the exact same thing as f(20)=40 though

Answer 18

Yeah :) but now that we have the answer, how do i "Check My Solution" or "Prove" it?
Because, to be honest proving my answers seems a bit more confusing when it comes to problems like this

Answer 19

prove it?

Answer 20

it is right there on the graph

Answer 21

So i;'d basically copy paste the graph over, show the transformations i made, and then show that they are indeed inverse?

Answer 22

I don't know...
I would just put the answer...
I would draw the inverse graph.
And interpret what f^(-1)(40)=20 means...

Answer 23

Alright, sounds great :) appreciate the help!!!

Answer 24

np