- #1
tiagomendes
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Prove that the vectors a=3i+j-4k
b= 5i-3j-2k
c= 4i-j-3k are COPLANAR
(axb)c=0
If (axb)c=0 then c is orthogonal to axb and therefore c is in the plane perpendicular to axb since axb is perpendicular to both a and b, both a,b,c are in the same plane perpendicular to axb.
My problem is that my answer when using the formula doesn't equal 0 meaning that it isn't coplanar which means its wrong because i have to prove it is. Can someone show me a walkthrough and how to use this formula because I am doing something wrong
b= 5i-3j-2k
c= 4i-j-3k are COPLANAR
Homework Equations
(axb)c=0
The Attempt at a Solution
If (axb)c=0 then c is orthogonal to axb and therefore c is in the plane perpendicular to axb since axb is perpendicular to both a and b, both a,b,c are in the same plane perpendicular to axb.
My problem is that my answer when using the formula doesn't equal 0 meaning that it isn't coplanar which means its wrong because i have to prove it is. Can someone show me a walkthrough and how to use this formula because I am doing something wrong