Question

Use interval notation to indicate all real numbers between and including −3 and 5.

Answer 1

[-3,5]

Explanation:

Interval notation is a shorthand way of writing and interval of values. To describe an interval, imagine the two endpoints on the number-line. Then, list the two endpoint values, leftmost point from the number-line first, separated by a comma. Lastly, include the appropriate brackets for each endpoint:

• Only two brackets total will be used for each interval, a bracket to start it, and one bracket to end it.
• If a number is included, a square bracket should be used -- either "[" or "]"
• If the endpoint number is not meant to be included, a 'curved bracket' (which we usually just call a parenthesis) should be used -- either "(" or ")"

For our situation, the two endpoints are -3 and 5. -3 is to the left of 5 on the number-line, so -3 should be listed first

`-3,5`

Lastly, the directions say "including -3 and 5", so both endpoints should be included.

• To include the -3 on the left, we'll use "["
• To include the 5 on the right, we'll use "]"

The final result for the interval is
`[-3,5]`