Question

The vector(s) which is/are coplanar with vectors i + j + 2k and i + 2j + k, are perpendicular to the vector i + j + k is/are

(A) j - k

(B) - i + j

(C) i - j

(D) - j + k

Answer 1

Correct option (A, D)

Explanation:

Let, vector a = i + j + 2k, vector b = i + 2j + k and  vector c = i + j + k

∴ A vector coplanar to vector a  and vector b, and perpendicular to vector c