A unit vector coplanar with `i+j+ 2k` and `i+2j+k` and perpendicular to `i+j+k` is

A vector coplanar with vector i+j and j+k and parallel to the vector 2i-2j-4k is

A unit vector perpendicular to 3i + j +2 k and 2i-j + k is

A unit vector perpendicular to 3i+4j" and "i-j+k is

If a=i+j-k,b=i-j+k and c is a unit vector perpendicular to the vector a and coplanar with a and b,then aunit vector d perpendicular to both a and c is

A unit vector perpendicular to 2i + 3j + 4k and 4i - 3j + 2k is