# Homework Help: Parallel/Orthogonal in Calc 3.

1. Sep 7, 2011

### tarheels88

1. The problem statement, all variables and given/known data
Let vector 'v'=<1,-1,5> and vector 'w'=<40,-19,-1>. Represent 'w' in the form of 'w'='g'+'h',
where 'g' is parallel to 'v', and 'h' is orthogonal to 'v'. This is related to the dot product. But I don't know where to begin

2. Relevant equations
'v' is a vector. 'g' is a vector. 'w' is a vector. 'h' is a vector

3. The attempt at a solution
So far I set up an equation <40,-19,-1>='g'+'h'
I doubt this is right so far. I know that g has to be a multiple of v and h has to = 0 in order for it to be orthogonal.

2. Sep 8, 2011

### lanedance

well what do you know about dot products? in particular consider
$$w \bullet v$$