Hi

Can someone tell me where i have gone wrong in the following question?

Given thatv=2i+ 2j+k,w= 3i-j+kfind a unit vector perpendicular to bothvandw.

unit vector = {axb}/{|axb|}

|a x b|=

a x b=i(2 x 1 - 1 x -1)-j(2 x 1 - 1 x 3)+k(2 x -1 - 2 x 3)

=i(2+1)-j(2-3)+k(-2-6)

=3i+j-8k

therefore unit vector = (3i+j-8k)

answer says its (-3i-j+8k)

P.S