<h3>Answer: Choice B</h3>
The set notation includes all values from -5 to 0, but the domain only includes the integer values
eg: something like -1.2 is in the second set, but it is not in the set {-5,-4,-3,-2,-1}
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Further explanation:
Let's go through the answer choices one by one
- A. This is false because 0 does not come before -5, but instead -5 is listed first. The order -5,-4,-3,-2,-1,0 is correct meaning that
is the correct order as well.
- B. This is true. A value like x = -1.2 is in the set
since -1.2 is between -5 and 0; but -1.2 is not in the set {-5, -4, -3, -2, -1, 0}. So the distinction is that we're either considering integers only or all real numbers in this interval. To ensure that we only look at integers, the student would have to write
. The portion
means "x is in the set of integers". The Z refers to the German word Zahlen, which translates to "numbers".
- C. This is false. The student used the correct inequality signs to indicate x is -5 or larger and also 0 or smaller; basically x is between -5 and 0 inclusive of both endpoints. The "or equal to" portions indicate we are keeping the endpoints and not excluding them.
- D. This is false. Writing
would not make any sense. This is because that compound inequality breaks down into
. Try to think of a number that is both smaller than -5 AND also larger than 0. It can't be done. No such number exists.