Vector coplanar question

[jarman007]

Homework Statement

The value of n so that vectors 2i + 3j - 2k , 5i + nj + k and -i + 2 j + 3k may be coplanar?

a)18 b)28 c)9 d)36


2. The attempt at a solution

I was not able to think of any step

so please help

 

[rl.bhat]

Hi jarman007, welcome to PF.
The vectors A, B and C are coplanar if A.(BXC) = 0

 

[jarman007]

thanks and please check my solution

BxC = 10k -15j + nk + 3ni + j +2i = (3n+2)i -14j + (10+n)k


A.(BxC)=6n+4-42-20-2n=0

therefore n = 58/4

 

[rl.bhat]

BxC = 10k -15j + nk + 3ni + j +2i = (3n+2)i -14j + (10+n)k
This calculation is wrong.
Check i and j coefficients. My answer is 18.

 

[jarman007]

thanks

got the answer