Next, to see this equation on a calculator we actually have to use two separate functions. This is because a sideways parabola is not a function — think back to the Vertical Line Test.
y=2sqrt(x) and y=- 2sqrt(x)
To enter these functions, push Y= and type them in two different rows. Then, push GRAPH to draw them.
Looking at the graph, we can see that the vertex occurs at (0,0) and that the parabola opens to the right.
