I would like to know what the $\displaystyle i,j,k$ stand for in things like:
$\displaystyle v=2i+j-k$
my guess: they stand for north, east, and ?forward?
Firstly,Originally Posted by Quick
it is $\displaystyle \bold{i}$ not $\displaystyle i$, if you are writing on paper and do not want to draw a bold line you write $\displaystyle \vec{i}$ (with an arrow on top).
Let me explain it differently.
This is a vector,
$\displaystyle \bold{v}=2\bold{i}+\bold{j}-\bold{k}$
where, $\displaystyle \bold{i},\bold{j},\bold{k}$ are called vector-components.
Basically you are in 3 dimensions. Instead of 2 (xy graph) you know have an xyz graph. So think of a point located at $\displaystyle (2,1,-1)$ now from that point draw a line to the orogin $\displaystyle (0,0,0)$ the resulting line would be called a vector defined by $\displaystyle 2\bold{i}+\bold{j}-\bold{k}$
so then $\displaystyle \bold{i}$ would be the x-coordinate, $\displaystyle \bold{j}$ would be y, and $\displaystyle \bold{k}$ would be zOriginally Posted by ThePerfectHacker
and the distance and direction between that point and the origin is the vector? seems logical to me
just a question about directions...
would I consider the y axis as elevation, like if I said the ball was thrown upward at 3 ft/s would be $\displaystyle 0\bold{i}+3\bold{j}+0\bold{k}$
would I consider the z axis moving forward, like If I said that a man walks forward at a pace of 1 ft/s would be $\displaystyle 0\bold{i}+0\bold{j}+1\bold{k}$