What is (-∞ , -1) ∪ [ 2 , +∞)

9514 1404 393

  interval notation for all numbers except those that are at least -1 and less than 2.

Step-by-step explanation:

The ∪ between the two sets of brackets indicates the "union" of two sets. The brackets on the left indicate the interval ...

  -∞ < x < -1 . . . . . for a value represented by x

The curved brackets ( ) indicate the end values of the interval are not included, which is why the < symbol is used, and not the ≤ symbol.

The brackets on the right indicate the interval ...

  2 ≤ x < +∞ . . . . . for a value represented by x

The square bracket [ ] is used to indicate the end value is included, which is why the ≤ symbol is used in relation to the end-value 2.

By convention, the interval notation lists the left end of the interval first, and always uses curved brackets for infinity.