my book says that if you have a parametrized line in 3 dimensions i.e.: x - 1 = 4t y - 5 = 3t z - 2 = 7t, the vector <4, 3, 7> (coefficients of t) is a vector parallel to that line. My notes clearely say that the vector <4, 3, 7> is a normal vector to the parametrized line. Which one is right? Thanks.