Question

if you vectors having same direction i.e. parallel, what is the test by which you can say that are indeed parallel?

Answer 1

for example:
if grad f(x,y,z)=i+j+k
how can you tell if it is in the direction of the vector f(x,y,z)?

Answer 2

oh nevermind. cross product must be 0

Answer 3

Parallel vectors are also scalar multiples of each other eg <1, 2, 3> and <2, 4, 6>

Answer 4

ahan. thanks,