# Why i-hat, j-hat, k-hat

1. Jun 20, 2011

### tony873004

Why are i, j, and k perfered in many texts to represent the 3 spacial dimensions instead of (what seems to me to be more intuitive) x, y, and z?

2. Jun 20, 2011

### Nabeshin

3. Jun 21, 2011

### DrGreg

By convention, i, j, k are vectors. x, y, z are coordinates. So you might have (in a cartesian coordinate system)
$$\textbf{r} = x\textbf{i} + y\textbf{j} + z\textbf{k}$$

4. Jun 21, 2011

### Superstring

It's just a convention. There's no special reason for it, probably other than the fact that they are less confusing than using $$\mathbf{ \hat{x}}$$ $$\mathbf{ \hat{y}}$$ and $$\mathbf{ \hat{z}}$$

5. Jun 21, 2011

### Studiot

More than that, they are unit vectors.

x. y and z extend from minus infinity to plus infinity.

6. Jul 7, 2011

### tony873004

Sorry, I kinda lost track of this thread, even thought it was my question. I was just tutoring someone in Physics, and her teacher used x-hat, y-hat, and z-hat. But unit vectors make total sense. Thanks everyone for the replies.