Is there more than one meaning of the notation f(x)=[x] ?

[objectivesea]

Is there more than one meaning of the notation "f(x)=[x]"?

In my real analysis textbook there is a question that says:

Decide whether f(x)=[x] is bounded above or below on the interval [0,a] where a is arbitrary, and whether the function takes on it's maximum or minimum value within that same interval.

This question is very straightforward, assuming [x]=x. But if that is the case, then the choice of notation is very strange.

Is there another way to interpret the notation's meaning?

 

[pwsnafu]

Usually, that's the "integer part" function. Eg f(3.12) = 3

 

[HallsofIvy]

Strictly speaking
\lfloor x\rfloor
which looks like [x] with missing upper serifs is the "integer part" of x (the largest integer less than or equal to x). If your text has all of the [ ] parts, I recommend you look through your textbook (perhaps there is an "index of symbols") or ask your teacher for the meaning of that symbol.