# Vector - points in same direction

1. Oct 23, 2008

### marionca57

I don't know how to make the vector arrow on top of the letter so I just underlined the vectors. Also I don't know how to make the square root symbol so I just type sqrt for it.

1. The problem statement, all variables and given/known data
Which points in the same direction as V = (-sqrt2, sqrt3, sqrt5)
a) 1/10 V
b) sqrt10/10 V
c) sqrt10 V
d) sqrt 10 V

2. Relevant equations

3. The attempt at a solution
I am not sure where to start other than calulating the sqrt of 2,3, and 5. My best guess would be c but I need to know why if that is correct or some help figuring it out.
Thanks,
Marion

2. Oct 23, 2008

### tiny-tim

Welcome to PF!

Hi Marion! Welcome to PF!

(have a square-root: √ )

On this forum, type vectors in bold.
(c and d look the same )

As you probably know, on this forum we don't tell you the answer, we just try to nudge you in the right direction.

What tests do you know for two vectors to be pointing in the same direction?

3. Nov 3, 2008

### jimvoit

It is a good idea to make carefull use of parentheses so that there is no
ambiguity as to the meaning of an expression.

Consider that for positive constants k, and vectors v, k v is in the same direction of v.