I am new to this forum. I've been programing for some time, and now starting my engineering degree. I am trying to find an online utility that will help me grasp the concept of irrational numbers (summary, multiplication, devision etc.) through trial and error. I am looking for an online tool that will give me a yes no answer if a number is rational or irratioonall.

Do you know of any such tools? I Hope this question is in the right stackexchange site.

  • $\begingroup$ Although you've gotten an answer, this is not the right place for this question. Just fyi. $\endgroup$
    – R.M
    Aug 27, 2012 at 6:46
  • 6
    $\begingroup$ What format do you have those numbers in? Any irrational number will have an infinite, non-periodic decimal expansion, so there is no obvious way to store it on a computer (and no real advantage to "small" numbers). $\endgroup$ Aug 27, 2012 at 8:26
  • 11
    $\begingroup$ Any number you can type in by entering a finite number of digits is always going to be rational. I guess you mean you want to enter expressions like $\sqrt{7}$, $\pi/5$, and so on, and see if they are rational. But this is a surprisingly hard problem in general: for example, nobody knows whether $\pi + e$ is rational or irrational. $\endgroup$
    – user856
    Aug 27, 2012 at 8:39
  • $\begingroup$ @RahulNarain: That would be good as an answer. $\endgroup$ Aug 27, 2012 at 15:24
  • $\begingroup$ But @Henning, I don't know if it answers the question. The question asks about numbers, I was only extrapolating about arbitrary expressions. $\endgroup$
    – user856
    Aug 27, 2012 at 17:29

1 Answer 1


You can simply try Wolfram|Alpha.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .