A mapping is shown in the diagram below.
Jan
Feb
Mar
28
29
30
31
Apr
This mapping is
1)
a function, because Feb has two outputs, 28
and 29
2) a function, because two inputs, Nan and Mar,
result in the output 31
3) not a function, because Feb has two outputs, 28
and 29
not a function, because two inputs, Jan and
Mar, result in the output 31