Question

Which relation is not a function?

[Control] A. ((6.5).(-6, 5). (5.-6)
[Control] B. ((6,-5). (-6, 5). (5.-6))
[Control] C. ((-6,-5). (6.-5. (5.-6)}
[Control] D. ((-6,5).(-6.-6).(-6.-5))

Answer 1

D.

Explanation:

That would be D because there is a repetition of x = -6.

-6 maps to -6, 5 and -5 which is not allowed in a function.

Functions can be one-to-one or many-to-one but not one-to-many.