Background: We are assuming that the elements of R∖QR∖Q are irrational number. If xx is irrational and rr is rational then y=x+ry=x+r is irrational. Also, if r≠0r≠0 then rxrx is irrational as well. Likewise, if a number is irrational then its reciprocal is irrational as well.
Theorem: Every interval (a,b) no matter how small, contains both rational and irrational numbers.