two vectors are orthogonal(perpendicular) if their dot-product is 0
so.. let's check that (1*-4) + (-2*8) -> -4-16 -> -20
so, they're not orthogonal
two vectors are parallel if one is the scalar multiplication of the other, namely, they're just multiples of each other
hmm let's see 1, -2, now if we do say -4<1,-2> we end up with < (-4*1) , (-4*-2)> which is < -4 , 8>
thus.. they're parallel then
