All Things Algebra Unit 3 Homework 2: Fact-Checking Common Solutions and Viral Study Hacks
Q1: Why is an arrow on a coordinate plane graph important for domain and range?
An arrow indicates that the line extends indefinitely in that direction toward positive or negative infinity. If a line moves left forever with an arrow, its domain begins at negative infinity (`-∞`), not at the edge of the printed coordinate grid.
Q2: How do I know whether to use brackets or parentheses in interval notation?
Use square brackets `[` or `]` when the endpoint number is included in the relation, marked by a solid dot or a continuous line. Use round parentheses `(` or `)` when the boundary point is excluded (an open circle) or when expressing infinity (`∞` or `-∞`).
Q3: Can a relation have repeating y-values and still be a function?
Yes. A relation can share identical y-values for different x-values. For example, `(2, 5)` and `(-2, 5)` form a valid function. A relation fails the function test only when a single x-value links to two or more different y-values, such as `(3, 4)` and `(3, 7)`.
