Find a unit vector which is perpendicular to both `vecA=3hati+hatj+2hatk and vecB=2hati-2hatj+4hatk`.

Explanation

The unit vector perpendicular to both `vecA and vecB`
`hatn=pm(vecAxxvecB)/(|vecAxxvecB|)`
Now, `vecAxx vecB =|{:(hati,hatj,hatk),(3,1,2),(2,-2,4):}| =8hati-8hatj-8hatk`
`therefore |vecAxxvecB|=8sqrt(3) therefore hatn=pm1/sqrt(3)(hati-hatj-hatk)`