Which relation is a function? {(1, 4), (2, 3), (3, 2), (4, 1)}

{(4, 2), (3, 3), (2, 4), (3, 2)}

{(1, −1), (−2, 2), (−1, 2), (1, −2)}

{(1, 2), (2, 3), (3, 2), (2, 1)}

A relation from a set X to a set Y is called a function if each element of X is related to exactly one element in Y. That is, given an element x in X, there is only one element in Y that x is related to.

Step-by-step explanation:

A relation from a set X to a set Y is called a function if each element of X is related to exactly one element in Y. That is, given an element x in X, there is only one element in Y that x is related to.

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13

the answer is -1 1/5, also a

hope i

-lavira : )