You are asked to sketch the graphs in this family not by plotting and joining points but by considering the general features of the graph of the rectangular hyperbola xy=1 and of transformations of this graph.

When you make your own pattern of hyperbolae using the equation
x2
a2
- y2
b2
= 1
you might like to try making the same transformations as those used in the example Ellipses where the family of equations is given by
x2
a2
+ y2
b2
= 1.
See the challenge Ellipses here.