1. ## vectors

if U=8i+4j-12j and V=i+2j-k, write U as the sum of a vecter parallel to V and a vector perpendicular to V

2. Originally Posted by rabih2011
if U=8i+4j-12j and V=i+2j-k, write U as the sum of a vecter parallel to V and a vector perpendicular to V
$U = V_{||} + V_ \bot$ where $V_{||} = \frac{{U \cdot V}}{{V \cdot V}}V$ and $V_ \bot = U - V_{||}$

3. thanks but how do i find V||?

4. Originally Posted by rabih2011
thanks but how do i find V||?
I showed you $V_{||} = \frac{{U \cdot V}}{{V \cdot V}}V$
Now do it.