determine whether the vectors u and v are parallel, orthogonal, or neither.
u = < 6, -2> , v = < 2, 6>

To check if two vectors are parallel, you can simply do a b/a check, if the ratio of one is the same as the other, that simply means the vectors are just multiple of each other and thus parallel.  Let's check.

6/-2 = -3/1                     6/2 = 3/1

nope, they're not parallel.

To check if two vectors are orthogonal(perpendicular), simply check their dot-product, if their dot-product is 0, then they're indeed perpendicular to each other, let's check



low and behold, their dot product is 0.