Interval notations

Each row of the table has equivalent expressions. Complete the following table and questions.

Example Inequality notation Set notation Interval notation
#1 -1 ≤ x < 10 { x | -1 ≤ x < 10} [-1, 10)
#2 x ≤ 5 or x > 1 { x | x > 1 or x ≤ 5} (-∞, -5] ∪ (1, ∞)
#3 x ≥ -5    
#4     (-∞, 3) ∪ (3, ∞)
#5   { x | x < 1 and x > -1 }  

What do the parentheses () mean for intervals?


What do the brackets [] mean for intervals?


What does the "sideways eight" mean?


What does the ∪ symbol mean?