Firstly, what is the domain of x? That is what values are restricted in all of these?
Once you figure that out, I would pick easy numbers to work with, meaning squares. Plot y(0), y(1), y(4), y(9) and you should start seeing the shape of the graph. The second two graphs are just variations of the first one.
There are other ways to find information about the graph, but that is throw Calculus or some intuitive thinking. The general shape should be starting at zero, going steeply up and leveling out the farther out on the x-axis you go.