What Does the -1 Index Mean in the Abbreviation km h^-1?

[Simonio]

I'm looking at a question that refers to kilometres per hour and uses the abbreviation\(km h^-1\)

It looks like a -1 index -could someone [point out to me what this means (I'm only just starting to get back into maths!).

Thanks

 

[Deveno]

You are probably referring to:

$\text{kmh}^{-1}$

which means the same thing as km/h, that is to say: "kilometers per hour".

The superscript "${}^{-1}$" typically means "inverse", in this case "multiplicative inverse", or in more common language, "reciprocal", that is to say:

$h^{-1} \stackrel{\text{def}}{=} \dfrac{1}{h}$

 

[MarkFL]

I'm looking at a question that refers to kilometres per hour and uses the abbreviation\(km h^-1\)

It looks like a -1 index -could someone [point out to me what this means (I'm only just starting to get back into maths!).

Thanks

Just a couple of $\LaTeX$ tips...

a) If you want to express units of measure, enclose them within the \text{} command so that they are not italicized like variables.

b) If an exponent has more than 1 character, enclose it within curly braces.

Thus, you could use the code:

\text{kmh}^{-1}

to get:

\(\displaystyle \text{kmh}^{-1}\)

Another tip: If you see a $\LaTeX$ expression and you would like to quickly see how it is done, this is, what code was used, right-click on the expression, and from the pop-up menu choose Show Math As ► TeX Commands, and a small pop-up window will contain the $\LaTeX$ code used to produce the result. You can then copy-paste the code and modify it for your own use in a post if you like.