Argh....stupid math problem

[SkyHog]

In my math class, I was given a problem as homework that I cannot find in my notes or covered in the chapter. The question is:

Given the function below, graph its domain on a number line. Be sure to show your work. Rememeber that no work means no credit!

f(x)= _2_
¯¯¯¯ x-3

Just in case that doesn't display properly (I tried!!) that's essentially "F of x = 2 over x minus 3"

 

[wsuffa]

In my math class, I was given a problem as homework that I cannot find in my notes or covered in the chapter. The question is:

Given the function below, graph its domain on a number line. Be sure to show your work. Rememeber that no work means no credit!

f(x)= _2_
¯¯¯¯ x-3

Just in case that doesn't display properly (I tried!!) that's essentially "F of x = 2 over x minus 3"

Hint: it's a straight line.

 

[msmspilot]

Hey skyhog,
I'm going to assume you know how to draw a number line.

The domain of any function is just the set of all the "stuff" you can plug into that function. if you have F(x)=2x, then the domain is all real numbers. if you have F(x)=squareroot(x), then the domain is all positive numbers and zero because the square root of a negative number isn't real.

So what you need to do is look at your function and figure out what, if any numbers would make your function either not real, or undefined.

I hate to just give away answers, so work with that and see where you get. if you need more help, i'm going to check the boards later tonight.

 

[SkyHog]

Hint: it's a straight line.

Yeah - I figured I need to get it into y=mx+b format, but I can't figure out how to get the x-2 away without completely messing up the format. I can get it to be (x-2)y=2, but that doesn't do me any good, as far as I can tell. I'm truly stumped (and this is a class that I technically tested out of, too!)

 

[msmspilot]

Think about the form 1/x. what number can you plug in for x that makes 1/x undefined? once you figure that out, look at your problem and see what looks similar about it.

Daniel

 

[Kelly]

it's not a straight line.... it doesn't fit into y=mx+b.... you can tell because if x=3
and
y=2/(x-3)

then y=2 divided by 0 ie undefined

now if you take the derivative of it... but that's next semester.

 

[Let'sgoflying!]

Rememeber that no work means no credit!

Does that mean credit given is proportional to work applied, regardless of results achieved??
If so, I need to call a lot of profs and teachers from a few years back and see what kind of compensation I am owed!

Good luck Nick sorry for the absence of help in this post.

 

[Kelly]

it should look like this but extending down and up forever just before and after "3"

"I'm an engineer, I have no social life and I can prove it mathmatically"

 

[SkyHog]

ok - so from what I can gather, making x=3 means it will be undefined, therefore, x cannot be three. From that, then, since the question is asking for a number line, then I would make it like:
(I apologize for the shotty artsmanship)

 

[msmspilot]

Looks like the number line I drew