Question

How do you solve and write the following in interval notation: y is at least 5?

Answer 1

Range: `[5, oo)`

Explanation:

FYI (general knowledge)

We are talking about the y-values, so we are dealing with the range.

Remember:

`[ or ]`(brackets) - include all numbers including the one inside the bracket(s)

`( or )`(parentheses) - include all numbers but the one noted inside the parentheses

For example:

`[ x , y)`

Here, the variable `x` is included as a solution, but the variable `y` is not.

FOR YOUR QUESTION

So for all `y` values at least `5`:

Use a bracket since it is at least:

`[5`

and since it is not specified that there is a limit number, we finish with infinity:

`[5,oo)`

Note that whenever `oo` is used in interval notation, it must be parentheses that close up the notation.