On part A it should be .
For part B they are asking you to show that at the two points where y is equal to 0, that the slopes are parellel. Of course, you need to find out where those two points are. Plugging in y=0 into your equation will show you where those two points are.
For part C, they are asking for the point's where the derivative of your equation is 0.
Hopefully this helps you a little bit.