I think $(0,2)\cup(2,3)$ is dense in [0,3] since the only problem point would be 2
but $B(2,r)\cup [0,3]$ is non-empty for all $r>0$
is this ok?
I think $(0,2)\cup(2,3)$ is dense in [0,3] since the only problem point would be 2
but $B(2,r)\cup [0,3]$ is non-empty for all $r>0$
is this ok?
Hint: What is the closure of $(0,2)\cup (2,3)$ in $[0,3]$?