1. Yes, it is a function.
Explanation: Each input (x-value) in the set {0, 1, 4, 8} maps to exactly one output (y-value). No x-value is repeated with a different y-value.
2. No, it is not a function.
Explanation: The input 5 maps to two different outputs (3 and 6), which violates the definition of a function where each input must have exactly one output.
3. [B] and [D] are NOT functions.
Explanation:
- Graph [B] fails the vertical line test — a vertical line intersects the graph at more than one point for some x-values.
- Graph [D] also fails the vertical line test — a vertical line through the center intersects the circle at two points.
Graphs [A] and [C] pass the vertical line test and are functions.
Parent Tip: Review the logic above to help your child master the concept of functions vertical line test worksheet.
