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

Jun 30, 2016

Range: $\left[5 , \infty\right)$

#### Explanation:

FYI (general knowledge)

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

Remember:

$\left[\mathmr{and}\right]$(brackets) - include all numbers including the one inside the bracket(s)

$\left(\mathmr{and}\right)$(parentheses) - include all numbers but the one noted inside the parentheses

For example:

$\left[x , y\right)$

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

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:

$\left[5 , \infty\right)$

Note that whenever $\infty$ is used in interval notation, it must be parentheses that close up the notation.