Question

Show that the four points having position vectors 6i - 7j, 16i - 19j - 4k, 3j - 6k, 2i + 5j + 5k are not coplanar.

Answer 1

Formula : -

Given: -

The four points are coplaner if vector AB, AC, AD are coplanar.

now, using

= 10(100 + 72) + 12( – 60 – 24) – 4( – 72 + 40)

= 840

≠0.

Hence the point are not coplanar