Question

Find a unit vector perpendicular to both of the vectors (3a + 2b) and vector (3a - 2b), where vector a = i + j + k, vector b = i + 2j + 3k.

Answer 1

Here vector (3a + 2b) = 5i + 7j + 9k, vector (3a - 2b) = i - j - 3k

Let vector r be perpendicular to the vectors (3a + 2b) and vector (3a - 2b).

Therefore, the unit vector perpendicular to both of the vectors (3a + 2b) and vector (3a - 2b) is,