Question

if a=i-2j-3k,b=2i+j-k and c=i+3j-2k, the find the value of [a*b].c

Answer 1

a = i - 2j - 3k

b= 2i + j -k

c = i + 3j - 2k

[a b ] c = [ (i - 2j - 3k ) (2i + j - k)] ( i + 3j - 2k)

= [ 2i^2 -2j^2 + 3k^2 - 3ij - 7ik -kj] ( i + 3j - 2k)

==> 2i^3-6j^3-6k^3 + 3i^2j-13i^2k - 11ij^2+ j^2k + 11jk^2 -16ijk