Set S consists of all positive integers

David Recine, Magoosh Tutor

"That are not equal to the square of an integer" basically means that the numbers in Set S do not have integers as square roots, and cannot be gotten from squaring other integers.

So for example, Set S would not include the number 4, because the number 4 is 2^2, and has a square root that's an integer: 2. 9 would also be excluded from Set S, since it's the result of 3 squared, 16 would not be in Set S because 16 is 4^2, and so on.

Jun 26, 2018 • Reply

Kevin Rocci, Magoosh Tutor

:)

Apr 25, 2014 • Reply

Kevin Rocci, Magoosh Tutor

True, Yosef!

https://www.youtube.com/watch?v=d5ab8BOu4LE

And for more information on picking numbers, here is a good article to look at:

http://magoosh.com/gre/2011/gre-math-review-quiz-plugging-in/

Apr 18, 2014 • Reply

ANMOL SETH

why is 0 not included?

Sep 14, 2016 • Reply

Cydney Seigerman, Magoosh Tutor

Hi Anmol,

Happy to help! Zero is not included because zero is not a positive integer. Zero is not a negative integer either! In fact, 0 is non-negative and non-positive. It's the only number that's considered "neutral" meaning it's neither negative nor positive. That means if you ever see a problem with the wording referring to "all positive integers", then 0 is absolutely not included :)

Hope this helps! :D

Sep 14, 2016 • Reply