Question

What is the cross product of `[2, 6, -1]` and `[1, 1, 18]`?

Answer 1

The cross product is `〈109,-37,-4〉`

Explanation:

The cross product of the 2 vectors is given by the determinant

`∣((veci,vecj,veck),(2,6,-1),(1,1,18))∣`

`=veci(108+1)-vecj(36+1)+veck(2-6)`

`109veci-37vecj-4veck`
So the cross product is `〈109,-37,-4〉`

Verifications, the dots products must `=0`

So, `〈109,-37,-4〉.〈2,6,-1〉=218-222+4=0`

`〈109,-37,-4〉.〈1,1,18〉=109-37-72=0`
So the cross product is perpendicular to the two vectors