what does the word [n] mean in math

Expert Answers
Borys Shumyatskiy eNotes educator| Certified Educator


For real number `x,` the symbol `[x]` means the integer part of `x,` i.e. the largest integer number not greater than `x.`

In decimal notation for positive `x=n.mkl...,`


For example, `[2.1]=2.`


For negative `x=-n.mkl...`

`[x]=-n-1` if some numbers `m, k, l, ...` aren't zero.

For example, `[-2.1]=-3.`


For any integer `x`    `[x]=x.`


Sometimes this function is called floor function and is denoted `|__x__|.`

The ceiling function is defined as the smallest integer not less than `x` and is denoted `|~x~|.`