Question

What is the cross product of `[9,4,-1]` and `[2, 1, -4]`?

Answer 1

`(-15,34,1)`

Explanation:

The cross product of two 3-dimesnional vectors in `RR^3` may be given as a matrix determinant

`(9,4,-1)xx(2,1,-4)=|(hati,hatj,hatk),(9,4,-1),(2,1,-4)|`

`hati(-16+1)-hatj(-36+2)+hatk(9-8)`

`=-15hati+34hatj+hatk`

`=(-15,34,1)`