Which of these words does not mean the same thing as domain?
a) input
b) first element
c) second element
d) x-value

Question

Which of these words does not mean the same thing as domain?
a) input
b) first element
c) second element
d) x-value

anonymous · Answer

Can there be more than one answer?

anonymous · Answer

I only see one correct answer...

anonymous · Answer

Domain is the input to a relation or rule... it's the number you put in, then the relation calculates the output.

You typically describe this when you have "x" and "y" by saying that you input an "x" value, and calculate the "y" value.

When you write ordered pairs with "x" and "y" coordinates, you list the "x" as the first element and the "y" as the 2nd element, like (x,y).

anonymous · Answer

@JakeV8 So you are saying that b, c, d are all answers?

    "Which of these words DOES NOT mean the same thing as domain? (emphasis added)"

anonymous · Answer

Three mean the same as domain, and one does not.

Domain cannot mean the same as "2nd element" in any definition that I know of... so answer C is correct... "2nd element" DOES NOT mean the same thing as domain.

Am I missing something?  Three of the terms appear more or less equivalent to domain, and answer C is more like "range", "y-value", or "output".  So C is correct.

anonymous · Answer

I thought 'element' was referring to a set?

$$     D:\{3, 4, 5, 6, 7\}   $$

Where the first element is 3 and the second element is 4.

And x-value is too specific of a term; domain is the set of x-values.

But you may be right.

anonymous · Answer

I don't really like the way they worded the question for the same reasons you point out.

If domain was literally the same thing as x value or first element, then you might write ordered pairs as (domain, range)... but clearly, a point is a single element of the domain with its associated range... writing a point as (domain, range) seems to me to misunderstand the terms.

But maybe this is one of those ones where teachers tell you to "it's ok if none of the answers seem perfect... just select the BEST answer"...   I always felt like that was lame way out of a problem.  I wish they would write better questions!! :)

anonymous · Answer

I think the answer should be x-value, cuz domain is the set of x-value.

anonymous · Answer

@JakeV8 Yeah; "choose the best answer" should be used sparingly if at all. :)