The position vectors of the points P, Q, R, S are \(\hat{i}\) + \(\hat{j}\) + \(\hat{k}\),2 \(\hat{i}\)+5\(\hat{j}\),3\(\hat{i}\)+2\(\hat{j}\)-3\(\hat{k}\), and \(\hat{i}\)-6\(\hat{j}\)-\(\hat{k}\), respectively. Prove that the line PQ and RS are parallel.