What is the cross product of #[3,-1,2]# and #[1,-2,-1] #?

1 Answer
Oct 2, 2016

Answer:

#5hati + 5hatj - 5hatk#

Explanation:

I use a 5 column matrix to compute the cross product:
|i....j.....k|i....j|
|3 -1....2|3 -1|
|1. -2. -1|1. -2|

#= hati{(-1)(-1) - (2)(-2)} + hatj{(2)(1) - (3)(-1)} + hatk{(3)(-2)-(-1)(1)}#

#= 5hati + 5hatj - 5hatk#