​If possible, sketch parabolas that satisfy each of the following conditions: 

1. An even function.

   Hint (a):

   An even function is symmetric across the $y$-axis.

2. An odd function.

   Hint (b):

   An even function has rotational symmetry about the origin.
   That is, the curve is the same in the first and third (or second and fourth) quadrants.

3. Neither even nor odd.

   Hint (c):

   Review the hints in parts (a) and (b). Sketch a parabola that does not satisfy these conditions. There are many possible correct answers.