In “Instrumental Flying“, we defined function as
From , we obtain
It means either or
But suggests
(see Exercise-1), contradicts the fact that
(see “Two Peas in a Pod, Part 2“).
Therefore,
i.e.,
We also defined a non-negative valued function :
Simplifying yields
It follows that either or
For both expressions’ right-hand side to be valid requires that . However, when
,
suggests that (see Exercise-2,3), contradicts (2).
Hence,
i.e.,
See also “A Relentless Pursuit“.
Exercise-1 Show that
Exercise-2 Without calculator or CAS, show that
Exercise-3 Prove (hint: see “Two Peas in a Pod, Part 2“)