1. Can a growth curve go BELOW the x axis?

Yes, a growth curve or exponential function such as y = 3x − 2 would drop 2 units below the x-axis.

It would cut the y-axis at y = -1.

2. Is the centre of a circle always the origin?

No. Some of the circles you will study later have centres in other places.

e.g. (x + 2)2 + (x + 3) 2= 81 has centre (-2, -3) and radius of 9 units.

3. On a hyperbola of the type xy = 4 the graph never cuts the x-axis or the y-axis

What are these two lines called in hyperbolas of this type?

They are called asymptotes.