Question

PLEASE HELP
Answer these three questions. There are 3 images attached below and they apply to each question, in order.
1)
a) Is this a function? Why or why not?
b) What is the domain?
c) What is the range?


2)
a) Is this a function? Why or why not?
b) What is the domain?
c) What is the range?



3)
a) Is this a function? Why or why not?
b) What is the domain?
c) What is the range?

Answer 1

1. a. Yes. Every point in the domain maps to only one point in the range.
1. b. Presumably, all values of $x\in\mathbb R$ belong to the domain.
1. c. As the graph depicts, the function takes on all values greater than and including $y=-4$, i.e. $y=f(x)\ge4$.

2. a. No. For all $x>2$, there are two values in the range that $x$ maps to. For instance, when $x=3$, we have, approximately, $y=\pm1.5$.
2. b. All $x\ge2$.
2. c. All $y\in\mathbb R$.

3. a. No. When $x=-3$, we have $y=\pm2$.
3. b. Assuming each point shown on the plot are all the points, then the domain is $x\in\{-3,-2,-1,0,1,3\}$.
3. c. $y\in\{\pm2,5,\pm1,3}$.