Help on Vectors & Geometry
posted by Wellness on .
(a) Given that A= 3i  j + 2k and
B=2i + 3j  k find A x B
(b) if A= i + j, B= 2i  3j + k and
C= 4j  3k
find (i) (AxB)x C
(ii) Ax(BxC)

I will do one. These are much easier to do as matrix multipication on your calc, I would learn to do that.
1)
AxB= (3ij+2k)x(2i+3jk)
= 3*3ixj3ixk2jxi+jxk+4kxi+6kxj
well, ixj=k
jxk=i
kxi=j (and the opposite order means )
AxB= 9k+3j+2k+i+4j6i
check that, and combine terms.