Let be three points in
not all on the same line, and let
be the plane they determine.
- If
with
prove that the point
is on
.
- Prove that all of the points on
are of the form
for
with
.
- Proof. Since
is the plane determined by the three points
we know
is the set of points
Let
. Then,
since
implies
- Proof. Let
be a point on
. Then, we know there exist
such that
But,
; thus,
for
I think there is a typo in the line after ¨Let s = q, \ t = r. Then,¨
should be: P – qP – rP + qQ + rR is on M