Problem 409 (difficulty: 4/10)
Does there exist a monotone function \(\displaystyle f\) such that
(1) \(\displaystyle D(f)=[0,1]\), \(\displaystyle R(f)=(0,1);\phantom{\,\cup [2,3]}\) (2) \(\displaystyle D(f)=[0,1]\), \(\displaystyle R(f)=[0,1]\cup [2,3]\);
(3) \(\displaystyle D(f)=[0,1]\), \(\displaystyle R(f)=[0,1)\cup [2,3]\); (4) \(\displaystyle D(f)=[0,1]\), \(\displaystyle R(f)=[0,1)\cup (2,3]\)?
Supported by the Higher Education Restructuring Fund allocated to ELTE by the Hungarian Government |