need help with domain and range

[proper tusk]

the domain is all the x values of the function (inputs)

the range is all the y-values of the function

you write them as intervals or sets

if you want to combine both you use the union symbol

I'm sort of confused about the arrows

yes

well

since the union is at -2 it's really one interval

what you wrote is the same as (-inf, 7]

but there's a part one to the question

do you know the vertical line test for graphs?

to see if they are functions

the definition of function means it sends one input of the domain to exactly one output of the range

so if one input has two outputs, this means it is not a function

on a graph, this corresponds to a vertical line intersecting two points on the graph

do you see any x value that maps to two different y values on the first graph

for part a?

read the question carefully: it says determine if it is a function first

for part b, range would be a set of points

domain is all x values where it is defined

this graph looks to be defined everywhere

range would be all y values

that are outputs

these are individual points it seems

I think it would be better to explain your reasoning and I can point you in the right direction