Talk:Whitney umbrella

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The parametric equation is not technically correct as the umbrella should include a handle. Hence it needs to be defined by its implicit form.

I've copied the old parametric equation below.

parametric equations

x \quad = \quad uv
y \quad = \quad u
z \quad= \quad v^2

--Pfafrich 21:31, 15 January 2006 (UTC)

Doing some research, people refer to the map R^2 \to R^3 as the Whitney umbrella, which is what is given by the parametric equations (the point being that the Whitney umbrella is a model of a singularity of a map). I've thus included the parametric version and the implicit version, with annotation. Nbarth 16:07, 21 December 2006 (UTC)

-- In the implicit equation x and y have to be interchanged. This can be verified by substituting x,y.z using the parametric equations. I made the correction. —Preceding unsigned comment added by 80.132.237.166 (talk) 18:19, 19 November 2007 (UTC)