Question

Are these functions?

Answer 1

Answer:

Relation 1 : Not a function

R2 : Function

R3: Function

R4: Not a function

Answer 2

You really should learn what a function is. It will help you in most of your future math courses.

(input, output) = (domain, range)

An input CANNOT go to two different outputs. This is not a function.

If the output is repeated, no problem. It is still a function but not ONE-TO-ONE.

Relation 1 is not a function because -7 goes to three different outputs.

Relation 2 is not function because cloud goes to two different outputs. Cloud is mapped to -6 and 6. Not a function.

Relation 3 is a function but it is not ONE-TO-ONE. Do you know why based on what I said above?

Relation 4 is not a function because -9 goes to two different outputs.

Understand?