Question

What is interval notation ?

Answer 1

A notation for representing an interval as a pair of numbers. The numbers are the endpoints of the interval. Parentheses and/or brackets are used to show whether the endpoints are excluded or included.

Answer 2

Example?

Answer 3

http://www.mathwords.com/i/interval_notation.htm

Answer 4

That's where I got the answer for you.

Answer 5

ok How would I write this in Interval Notation?

x < -2 or x >= 1

Answer 6

@Youth ?

Answer 7

(- ~, -2)

Answer 8

the interval notation for x < -2 or x >= 1

Simplify x<-2
Simplify x>=1
Therefore, x<-2 or x>=1
Display the interval notation and set builder notation for x<-2orx≥1

Since we have an or statement, we break this up into two pieces
Piece 1 → x<-2
Piece 2 → x≥1

Evaluate Piece 1
You entered the less than sign in the expression x<-2
We start with the right side of the interval notation
Build the interval notation for x:
Because you entered an equal sign, this translates to ) since we include the number -2
Based on the < you entered, the left side of the interval notation will extend to negative infinity, which is denoted as -∞

(-∞,-2)

Set Builder Notation for x:
{ x | x<-2 } where | denotes such that

Evaluate Piece 2
You entered the greater than or equal to sign in the expression x≥1
We start with the left side of the interval notation
Build the interval notation for x:
Because you entered an equal sign, this translates to [ since we include the number 1
Based on the < you entered, the right side of the interval notation will extend to positive infinity, which is denoted as +∞

[1,+∞)

Set Builder Notation for x:
{ x | x<-2 } where | denotes such that

Now we take our two pieces and form our interval notation for x:
(-∞,-2) U [1,+∞)


Display the literal representation for x
1,2,3,4,5,6,7,8,9,10,11,...,∞

Answer 9

(1,~)

Answer 10

@confluxepic

Answer 11

Didn't have the weird infinity sign but those were the answers.

Answer 12

Interval notation just allows you to rewrite something you already know. I'll give a few examples, first in words, then with less than/greater than/equal to signs and then in interval notation:

In words: All the numbers between 3 and 8 but not including them!
In symbols: 3 < x < 8
In interval notation (3,8)

Let's suppose we want to include 8 though, we would then write it as: \[3 < x \le 8\]\[(3,8]\]
So we just changed the end parenthesis to a square bracket! There are a few more rules, but you can ask us about them as they come up.

Answer 13

Another note, since you can never get to infinity, if you want to represent all the numbers greater than or equal to 7 for example, you will always use a parenthesis, not a square bracket, so that would look like x>7 in symbols and [7,infinty) in interval notation.

Answer 14

Thanks :)