This graph is very confusing,please help (pic)

[Lilian1234]

Hello,



Does anyone know f(-2)=? of this graph?

I tried to find the answer and I ended up with -3, but then i realized that the line ALSO crosses -4

Please help u__u

 

[Jt00]

Not sure what you mean. What is the function of this graph? If you didn't get a function with the graph, approximate. If it truly is a function, each x value will have only 1 y value.

 

[Lilian1234]

Not sure what you mean. What is the function of this graph? If you didn't get a function with the graph, approximate. If it truly is a function, each x value will have only 1 y value.

I'm not exactly sure what you mean.

I didn't get any function.
The question was "Use the graph of the function to find the following:
f(-2)=__ "


My teacher didn't mention anything about approximating..
He tells us to locate the x point and then see where the line hits in y-axis
In this graph it's both passing the -3 and -4

I'm usually okay with other graphs of similar kind but this one is a bit confusing.

 

[pka]

The question was "Use the graph of the function to find the following:
f(-2)=__ "

Do you realize that the posted graph is difficult to read?
But it appears to me that \(\displaystyle f(-2)=-4\).

 

[Lilian1234]

Do you realize that the posted graph is difficult to read?
But it appears to me that \(\displaystyle f(-2)=-4\).

Sorry
Here's a bigger version



What makes you think it's -4? why not -3?

EDIT: darn, this website doesn't allow big images apparently...

Here's a link of a bigger picture:
http://oi39.tinypic.com/2hz46ch.jpg

 

[Lilian1234]

Alright, -4 is correct ^___^

Do you know the domain of this graph, also?

 

[pka]

Here's a link of a bigger picture:
http://oi39.tinypic.com/2hz46ch.jpg

Using the link, it is very clear that \(\displaystyle f(-2)=-4\).
The domain is \(\displaystyle (-\infty,\infty).\)

 

[Lilian1234]

Using the link, it is very clear that \(\displaystyle f(-2)=-4\).
The domain is \(\displaystyle (-\infty,\infty).\)

Are you sure?

Because the options for this question are:

1) all the real numbers
2) {xl - 10 < x ≤ 10}
3) {xl - negative infinity < x ≤ 0}
4) {xl 0 ≤ x positive infinity}

 

[pka]

Are you sure?
Because the options for this question are:
1) all the real numbers
2) {xl - 10 < x ≤ 10}
3) {xl - negative infinity < x ≤ 0}
4) {xl 0 ≤ x positive infinity}

\(\displaystyle (-\infty,\infty)=\text{ all real numbers .}\)

 

[Lilian1234]

\(\displaystyle (-\infty,\infty)=\text{ all real numbers .}\)

Uh-huh! =)

Okay, what about all the x-values such that f(x)=-4?

I'm sorry for the many questions but I'm practicing for a test and I don't seem to get a few things.


So if y = -4, then x = -1, -2, -3, -4, -5, -6, -7, -8, -9, -10?
Or is x = -2?

 

[tkhunny]

You don't seem to have the idea. f(-2) is only the value AT x = -2. It is NOT all the values between x = -1 and x = -3. There is only one value AT x = -2.

 

[Lilian1234]

You don't seem to have the idea. f(-2) is only the value AT x = -2. It is NOT all the values between x = -1 and x = -3. There is only one value AT x = -2.

I figured.



But in the case of f(x)=-4, I'm supposed to find x so maybe that's different?
It's asking me to use comas to separate numbers, meaning there will be more than one number!

I don't think x = -2