The vector(s) which is/are coplanar with vectors and

MATHEMATICS · Single correct · A Level · Mathematics · Vectors · Vectors

Problem

The vector(s) which is/are coplanar with vectors

\hat{i} + \hat{j} + 2\hat{k}

and

\hat{i} + 2\hat{j} + \hat{k}

, and are perpendicular to the vector

\hat{i} + \hat{j} + \hat{k}

, is/are: (1)

\hat{j} - \hat{k}

(2)

-\hat{i} + \hat{j}

(3)

\hat{i} - \hat{j}

(4)

-\hat{j} + \hat{k}