What is the cross product of #[2,4,5]# and #[0,1,2] #?

1 Answer
Oct 28, 2016

Answer:

The cross product is #〈3,-4,2〉#

Explanation:

The cross product of 2 vectors #vecu=〈u_1,u_2,u_3〉# and #vecv=〈v_1,v_2,v_3〉# is given by

#vecu#x#vecv# #=〈u_2v_3-u_3v_2,u_3v_1-u_1v_3,u_1v_2-u_2v_1〉#
This vector is perpendicular to #vecu# and #vecv#

So the cross product of #〈2,4,5〉# and #〈0,1,2〉# is #〈3,-4,2〉#

Verification by making the dot product
#〈2,4,5〉.〈3,-4,2〉=6-16+10=0#
and #〈0,1,2〉.〈3,-4,2〉=0-4+4=0#

As both dot products are #=0# so the vector is perpendicular to the other 2 vectors