AD = DB
Angle ADE = Angle CDB
Angle DAE = Angle DBC (Alternate angles)
Angle DEA = Angle DCB (Alternate angles)
Since you have two congruent angles and one congruent side, triangle ADE is congruent to triangle CDB. This means that DE is congruent to DC implying D is the midpoint of CE.
Answer:
Let's put the chart into ordered pairs:
(x, y)
(2,1)
(3,4)
(3,3)
(4,2)
(5,5)
In bold, we see that there are two y-values at x=3. This means that this relation fails the vertical line test (two points on the same verticle line). This is not a function.
The answer options may be mis-written.
The answer is no, because one x value corresponds to more than one y-value.