Find the angle between the vectors `hati-2hatj+3hatk and 3hati-2hatj+hatk`.

Explanation

the given vectors are
`|oversettoa|= sqrt(1^(2)+(-2)^(2)+3^(2))=sqrt(1+4+9)= sqrt14`
`|vecb|= sqrt(3^(2)+(-2)^(2)+1^(2))=sqrt(9+4+1)= sqrt14`
now, `oversettoa.oversetto= (hati-2hatj+3hatk).(3hati-2hatj+hatk)`
= 1.3+ (-2)(-2)+ 3.1
= 3+4+3
= 10
now , `oversettoa.oversetb= |oversettoa||oversettob|costheta.`
`10 = sqrt14sqrt14costheta`.
` cos theta= 10/14`
`theta= cos^(-1)(5/7)`