Find the value of 'p' for which the vectors 3i + 2j + 9k and i - 2pj + 3k are parallel.
Since given two vectors are parallel.
⇒ 3/1 = 2/-2p = 9/3 ⇒ 3/1 = 2/-2p
⇒ - 6p = 2 ⇒ p = - 1/3
