Question

What is interval notation

Answer 1

Interval notation is a way to denote a connected subset of the real line. For example the set { x | a < x < b } is written as (a,b) in interval notation.

Answer 2

Example: The numbers from 1 to 2 on the real line, INCLUDING 1 and 2 themselves is denoted by [1,2]. The same interval WITHOUT the endpoints 1 and 2 is denoted (1,2). Including just the endpoint 1 and not the 2 is [1,2). On the other hand (1,2] means the interval excluding the 1 and including the 2.

Answer 3

what if i have x<-1 and x>1/2
How do i put that in interval notation

Answer 4

That is the empty set.

Answer 5

Because if you have a number that is smaller than -1 it can not be bigger than 1/2 (think about it!).