The triangle inequality comes in two versions.
Theorem
If
then
Proof:
![]()
![]()
![]()
![]()
![]()
![]()
![]()
-
is proved.
For part 2. note that![]()
so that
by part 1.
so that![]()
Similarly![]()
Since
we have
so that 2. follows.
The triangle inequality comes in two versions.
Theorem
If
then
![]()
![]()
Proof:
![]()
![]()
![]()
![]()
![]()
![]()
![]()
is proved.
For part 2. note that![]()
so that
by part 1.
so that![]()
Similarly![]()
Since
we have
so that 2. follows.