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Talk:Circumconic and inconic

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Inconsistent names: in the first section a, b, c, A, B and C are defined, but u, v and w are used instead.

Parabola as inconic?

[edit]

In the section "Other features", the first item under 'Inconics" says:

  • The general inconic reduces to a parabola if and only if
ubc + vca + wab = 0.

This is uncited, and I don't understand it. How can a parabola, which is unbounded, be an inconic, which is bounded by the triangle? And this equation seems to say that three positives sum to zero, implying that the equation doesn't describe anything. Someone have a clarification? Loraof (talk) 18:51, 25 September 2014 (UTC)[reply]

Got it now. The "inconic" need not be inside the triangle. It can be tangent to two extended sides and externally tangent to the third side. I'll clarify in the article. Loraof (talk) 22:30, 25 September 2014 (UTC)[reply]