- #1
Telemachus
- 835
- 30
Hi there. I'm working with some notions on functional analysis. I have this exercise, which says: Find all the metrics on a set X consisting of two points.
So I have this set
[tex]X=(x,y)[/tex]
(I don't know if this is the right way on defining a set, so I'm just trying).
The metric's d which I must find, should accomplish:
M1) d is real valued, finite and nonnegative.
M2)d(x,y)=0 if and only if x=y.
M3)d(x,y)=d(y,x)
M4)[tex]d(x,y)\leq d(x,z)+d(z,y)[/tex]
So here is the deal, as I have only two points, (x,y) on my set, I think that M4) could never be accomplished, so there are no possible metrics for this set.
Is this right?
So I have this set
[tex]X=(x,y)[/tex]
(I don't know if this is the right way on defining a set, so I'm just trying).
The metric's d which I must find, should accomplish:
M1) d is real valued, finite and nonnegative.
M2)d(x,y)=0 if and only if x=y.
M3)d(x,y)=d(y,x)
M4)[tex]d(x,y)\leq d(x,z)+d(z,y)[/tex]
So here is the deal, as I have only two points, (x,y) on my set, I think that M4) could never be accomplished, so there are no possible metrics for this set.
Is this right?