What is the interval set notation of -7 -3?

Answer 1

-4

Answer 2

-7 -3 is not an interval set notation. In general, an interval set notation consists of two brackets: either round () or square [] within which are two numbers. The infimum of the interval first, separated by a comma from the supremum. It is also necessary to define the superset of which the interval is a subset: it could, for example, be integers, rationals or reals.

A round bracket indicated a strict inequality, a square bracket indicated an inequality that is not strict.

The terms infimum and supremum are used rather than minimum and maximum because, if the inequality is strict, the numbers will not belong to the set.

Thus, for example,

[-7, -3) is equivalent to -7 ≤ x < -3, while

(-7, -3] is equivalent to -7 < x ≤ -3

where x is a Real number.

In the first example, -3 does not belong to the set and so cannot be said to be the maximum value in the set.