Using the triangle inequality show and are in with , then open intervals centered at and centered at b, both with radius
so far all I have is
now I'm not sure if what I'm doing is right:
?
I completely overlooked that part of the question. But I did found a prove for this statement but am still lost as to how it was done, even after asking my prof.
This is what I found:
suppose is in
which is apparently a contradiction.
If anyone could clarify this, it would help me out a lot.