Find a unit vector perpendicular to each of the vectors `hati+2hatj-3hatk` and `hati-2hatj+hatk`.

Explanation

Let `vecA=hati+2hatj-3hatk`
`vecB=hati-2hatj+hatk`
and let `vecC` is the vector given by the cross producty of `vecA`, `vecB` and `vecC` is perpendicular to the plane containing `vecA` and `vecB`
`vecC=vecAxxvecB`
Using Determinant method
`|{:(hati,hatj,hatk),(1,-2,-3),(1,-2,1):}|=hati(-9+8)-hatj(6-4)+hatk(-4+3)=(-hati-2hatj-hatk)`