In the first image, two graphs show intervals that need to be expressed using interval notation.

Question 1 (Top Graph)

This graph shows a closed interval from $1$ to $3$, inclusive of both endpoints. The blue dots at $1$ and $3$ indicate that both endpoints are included.

Interval Notation: $[1, 3]$

Question 2 (Bottom Graph)

This graph shows two intervals:

1. An interval from $-5$ to $-3$, inclusive of $-5$ but not $-3$.
2. Another interval from $3$ to $5$, excluding $3$ but including $5$.

Interval Notation: $[-5, -3) \cup (3, 5]$

In this notation, $[ ]$ means the endpoint is included, and $( )$ means the endpoint is excluded. The symbol $\cup$ represents the union of two intervals.

Would you like more details or have any questions?

Here are five related questions to deepen your understanding:

1. What is the difference between open and closed intervals?
2. How would you write the union of two non-overlapping intervals in interval notation?
3. Can an interval extend to infinity, and if so, how is it written?
4. What is the graphical interpretation of a point being included or excluded in an interval?
5. How do you convert inequalities into interval notation?

Tip: When writing intervals involving infinity, always use parentheses since infinity itself is never a specific, reachable value.