hello everyone, i understand the dot product and its properties but i don't get what they want! They say.... The dot product of two vectors are perpendicular if a.b = 0. Then any vector in R^3 perpendicular to -5 -6 -3 note: that is a matrix above. can be written in the form: and it looks like parameteric forum they want, because they want a column of s and a column of t. but i don't see where i'm suppose to find more numbers.