Coplaner Help

[ballaholic8]

Hey guys I was having some trouble with this question. take a look at it.

Are the four points A(1,-1,-1), B(0,4,-4), C(-1,6,-5) and D(-1,0,-1) coplaner? justify your answer.

I am unsure about the steps needed to verify this. please help.

 

[tkhunny]

1) Use A and B to get a direction vector.

2) Use A and C to get another direction vector.

3) Find the Cross Product of the two vectors to create a normal to the plan containing A, B, and C

4) Write the equation of the plane.

5) Substitute D and see if it's there.

 

[Deleted member 4993]

Hey guys I was having some trouble with this question. take a look at it.

Are the four points A(1,-1,-1), B(0,4,-4), C(-1,6,-5) and D(-1,0,-1) coplaner? justify your answer.

I am unsure about the steps needed to verify this. please help.

Create vectors AB, AC and AD

If AB, AD and AC are co-planar, then

AB•(AC x AD) = 0