Answer:
Option a
Step-by-step explanation:
A function is a relationship between two sets called domain and co domain where there is one output for every input. If you have more than one output for a particular input, i.e. if the mapping of elements of A to B are not unique, then the quantities represent a relation. A graph of a relationship can be shown to be a function using the vertical line test, which says that at any point if a vertical line makes two intercepts of the curve, the curve cannot be a function.
Given are two sets with {1,2,3,4,5,6} and {2,3,4,5,6,7} where there is a mapping.
We find that while 1,3 have unique mappings 2 does not have an image at all while 4 and 5 have the same image.
Since there is an element in the I set which does not have an image, this cannot be a function.
Option a
