1) function 2) not a function
the first one is a function because its y values are the same number (3), which means it is a horizontal line and horizontal lines are functions.
the second one is not a function because the coordinates cannot have different inputs but different outputs. each input must have only one output.
the coordinates for the second one are:
(2,5); (1,1); (1,2); (3,2)
and a function cannot have two same x-coordinates. it must pass the vertical line test which is a way to tell if something is a function or not. since the second graph does not pass the vertical line test, it is not a function
hope this helps :)