Question

A unit vector orthogonal to both a=<−2, 0, −1> and b=i−j−k is u= ?

Answer 1

the cross of the 2

Answer 2

so that gives me <-1,-2, 2>, but that's wrong?

Answer 3

-2 0 -1
1 -1 -1
--------
0(-1)-(-1)(-1) = -1

-1(1)-

is your cross right? because thats just the vector to it; you have to then divide out the magnitude to get it to a unit size

Answer 4

and then my mag. is 3, then?

Answer 5

so all the values i listed in my cross product, divided by 3?

Answer 6

lets assume your cross is right and go with it :)

sqrt(1+4+4) = sqrt(9) = 3, yes

Answer 7

divide out the 3 to get it to unit length, a length of 1