l -1 2 l l x l = l 2 l
l 1 -2 l l y l l 1 l
Show that the two lines are parallel and so never cross.
The Attempt at a Solution
I have attempted it, and so far all i have done is find the determentant. When i do this, i get zero:
det = ad - bc
= (-1*-2) - (2*1) = 0
So, is this all I have to do to prove that the lines are parallel?