Warm-up

What do you notice about this image?

A graph of an implicit curve

Are there any questions that you would like to ask about it?

  • Does this image represent one ‘curve’ or two separate curves?

  • Is there an equation that can describe some or all of this image?

  • The graph looks symmetrical about the \(y\)-axis – is this really the case?

  • Can you think of other graphs that exhibit similar properties? For example, graphs that are always positive?