Why Use i, j, and k as Unit Vectors Instead of x, y, and z?

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i, j, and k are preferred in many texts to represent the three spatial dimensions because they denote unit vectors, while x, y, and z refer to coordinates. This distinction helps reduce confusion, particularly in vector notation. The use of i, j, and k is a convention that simplifies mathematical expressions in physics and engineering. Unlike x, y, and z, which can extend infinitely in both directions, unit vectors provide a clear representation of direction. Overall, the choice of notation is rooted in convention rather than any inherent superiority.
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Why are i, j, and k perfered in many texts to represent the 3 spatial dimensions instead of (what seems to me to be more intuitive) x, y, and z?
 
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tony873004 said:
Why are i, j, and k perfered in many texts to represent the 3 spatial dimensions instead of (what seems to me to be more intuitive) x, y, and z?
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}
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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}}
 
By convention, i, j, k are vectors.

More than that, they are unit vectors.

x. y and z extend from minus infinity to plus infinity.
 
Studiot said:
More than that, they are unit vectors.

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

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.
 
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