Let be a point in
and let
be a line containing
and parallel to the vector
. Determine which of the following points are also on
.
-
;
-
;
-
;
-
;
-
.
Given a point




- If
were on
then we must have some
such that
From the first equation, this requires
, but then neither of the other two equations can hold. Hence, there is no
such that
so
is not on the line.
- If
were on
then we must have some
such that
From the first equation, this requires
, but then neither of the other two equations can hold. Hence, there is no
such that
so
is not on the line.
- If
is on
then we must have some
such that
From the first equation we have
. This value of
also satisfies the other two equations. Hence,
for
. Therefore,
is on the line.
- If
is on
then we must have some
such that
From the first equation we have
. This value of
also satisfies the other two equations. Hence,
for
. Therefore,
is on the line.
- If
is on
then we must have some
such that
From the first equation we have
. This value of
also satisfies the other two equations. Hence,
for
. Therefore,
is on the line.