Answer:
1. Yes
2. No
3. Yes
4. Yes
Step-by-step explanation:
#1
Yes, this is a function.
None of the x-values have more than one possible value for y. None of the x-values are repeated in this table.
#2
No, this is not a function.
For each and every value of x, there can only be one y. The x-value 13 has two possible values of y, 4 and -4. This is represented in the coordinates (13, 4) and (13, -4).
#3
Yes, this is a function.
The graph passes the vertical line test. If you were the pass a vertical line through the graph, it would only be touching the graph once, wherever the vertical line is placed.
#4
Yes, this is a function.
The equation given is a quadratic equation for an original parabola. All parabolas, when not inverse, are functions. This parabola opens down, so it will pass the vertical line test.