1. The problem statement, all variables and given/known data What is the condition of two vectors to be parallel? if A= A1i+A2j+A3k and B=B1i+B2j+B3k then what is the condition that the two vectors are parallel.. 2. Relevant equations A*B=AB sin(theeta) 3. The attempt at a solution by cross product i find the condition A1/B1=A2/B2=A3/B3 .... under which determinant becomes equal to to 0. which is the condition for parallel..theeta = 0 so sin 0 = 0 ... kindly confirm is it write or wrong.