Answer:
options 1,3,4 are functions.
Step-by-step explanation:
RULE: a relation is said to be a function if every element in the domain ( the numbers in the left side in the below sets) is related to only one number ( number on the right side in the below sets).
Let us check each option one by one:
1. 3 2
9 1
-4 7
0 -2
here each number on the left side is mapped to or is related to one number only.
so this relation is a function
2. 7 1
-5 2,3
1 0
here, "-5" is mapped to two different numbers. so this relation is not a function.
3. -2 -4
2 4
6 8
-6 -8
here each number on the left side is mapped to or is related to one number only.
so this relation is a function
4. 1 3
-1 3
2 3
-2 3
here each number on the left side is mapped to or is related to one number only.
so this relation is a function.
even if it is related to the same number, it doesn't matter.
it should follow the above given rule that's it.
