Quant Flashcard Group 6 Question 5

GRE Quant Problem Solving
1

Hello!

For question 5 on the group 6 quiz that asks for functions that have the same domain and range the correct answers as explained in the video are |x| and sqrt(x^2).

I am confused why 1/x which has a domain of all values except for 0 and a range of all values except for 0 and x^3 that has a domain and range of all reals are not counted as correct answers.

In addition for the two correct answers, my thought was that the domain for these functions were all reals, however the range would be all values greater than zero meaning they do not have the same domain and range.

Please let me know if i’m off base here or am missing something

Thank you!

2

Because if x = 0, then 1/x cannot be defined.

3

Yes so in that case 0 would be in neither the domain nor the range and so it would be (-∞,0) ∪ (0, ∞) for both of them, no?

4

It’s just a wording issue - this has been fixed. Take a look at the question now.

5

Ah excellent not domain/range for the individual functions themselves but for the pair of functions. Thank you for the clarification, the question is more clear now