Question

Show that the 4 points
P
1
= (0
;
0
;
0)
;P
2
= (2
;
3
;
0)
;P
3
= (1
;
1
;
1)
;P
4
= (1
;
4
;
1)
are coplanar (they lie on the same plane), and nd the equation of the plane that contains
them.