Talk:Lemniscate of Bernoulli

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1. How can I use the Lemniscate equation (x² + y²)² = a²(x² − y²) to come up with a graph?
2. Is there a mathematical connection to the similar looking Lissajous figures? --Abdull 18:06, 27 May 2006 (UTC)
3. This article gives the rectangular formula as (x² + y²)² = 2a²(x² − y²). Meanwhile, Schaum's (ISBN 0070382034) says (x² + y²)² = a²(x² − y²) -- note the factor of 2 is missing from the right-hand member. Either formula generates a lemniscate. Also, MathWorld says (x² + y²)² = 2c²(x² − y²) Later, MW gives two polar formulas: r² = 2c²cos(2θ) and r² = a²cos(2θ), noting that 2c² = a². We can make this Wikipedia article more consistent with other mathematical literature by changing (x² + y²)² = 2a²(x² − y²) to (x² + y²)² = a²(x² − y²), and noting that some authorities write (x² + y²)² = 2c²(x² − y²). Xovimat 16:16, 6 October 2007 (UTC)

[edit] derivative formulas

It's unclear what is meant by 'unbounded' in the formulas for the first and second derivates of y (respectively x) when thought of as a function of x (respectively y). Could someone please clarify what that is supposed to mean?Jrdodge (talk) 20:10, 17 November 2007 (UTC)