Find a vector such that and for the following vectors ,

- ;
- ;
- ;
- .

- If then letting we have
Since we have therefore,

Therefore, or .

- If then letting we have
Since we have therefore,

Therefore, or .

- If then letting we have
Since we have therefore,

Therefore, or .

- If then letting we have
Since we have therefore,

(The final equalities follow from .) Therefore we have or .