Suppose that in a certain basis B = (x,y,z), vector u is: u = 2x+3y-z. Find a unit vector with the same direction as u.

Question

Thank you

Answer 1

|u| = sqrt (2+9+1) = sqrt(12) = 2 sqrt(3)

unit vector = ( 1/{2 sqt3} ) u

= (1/6) sqrt 3 (2i+3j-k)

Answer 2

how did you get (2+9+1)?

Thank you