What is the domain for the following function?
y= (2x)/(x-3)

A. {all real numbers}
B. {x=/-3}
C. {x=/3}
D. {x=/0}

I think it is C.?

Please help and Explain. Thank you!

Question

What is the domain for the following function?
y= (2x)/(x-3)

A. {all real numbers}
B. {x=/-3}
C. {x=/3}
D. {x=/0}

I think it is C.?

Please help and Explain. Thank you!

kj4uts · Answer

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castiel · Answer

Domain means what inputs (x) you can use in your function to get an output (y). In your case if you use x=3 you would get $$\frac{ 2x }{0 }$$ which would break the world so if there is any justice in the world then 3 is not in the domain. But if you use any other x you'll get some number so that's okay. Even 0 is okay since 0/-3 = 0

kj4uts · Answer

ok thanks so yours saying 0 and 3? cause i have to choose one.

castiel · Answer

Also remember if you have $$\sqrt{x}$$ x has to be bigger or equal to zero.

castiel · Answer

no no, I meant 0 is in the domain because you are getting an output. If you choose 3 you would not get an output so 3 is not in the domain

kj4uts · Answer

ok im still a little confused as to what it is.

castiel · Answer

Basically when you get these type of functions remember that$$denominator \neq0$$

castiel · Answer

so you have $$x-3\neq0$$

castiel · Answer

$$x \neq3$$

castiel · Answer

Every number except 3 is in the domain

kj4uts · Answer

would this help in any way: http://www.wolframalpha.com/input/?i=y%3D%282x%29%2F%28x-3%29

castiel · Answer

c is the answer, because it says that the answer is all real number EXCEPT 3