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Aug 31, 2016 at 23:30 comment added KConrad @TheNumber23 stereographic projection is $\mathbf P^1(\mathbf C)$, and the projective plane is $\mathbf P^2(\mathbf R)$. The interpretation of asymptotes to real algebraic curves in $\mathbf R^2$ as tangent lines to missing points on the curve that you can find in $\mathbf P^2(\mathbf R)$ does not work if you extend the plane by just one point with stereographic projective: different asymptotes are typically tangent lines to different missing points that are revealed in $\mathbf P^2(\mathbf R)$.
Aug 31, 2016 at 22:04 comment added TheNumber23 @KConrad In what sense is the projective plane a better extension of the plane than sterographic projection? In particular what reasons would any of these students understand?
Nov 21, 2015 at 16:57 history edited KConrad CC BY-SA 3.0
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Jul 12, 2010 at 20:55 comment added David Corwin @KConrad: These days, I think it's common to call Michael Artin's Algebra a classic. There also is some introductory material to algebraic geometry, so I assume he is talking about that.
Apr 4, 2010 at 12:03 comment added Dror Speiser @Franz: Solving quadratic equations appears in Diophantus' Arithmetica.
Apr 3, 2010 at 21:32 history edited KConrad CC BY-SA 2.5
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Apr 2, 2010 at 21:56 history edited KConrad CC BY-SA 2.5
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Apr 2, 2010 at 18:32 history edited KConrad CC BY-SA 2.5
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Apr 2, 2010 at 15:31 comment added Anonymous KConrad's answer is great!
Apr 2, 2010 at 12:35 comment added Franz Lemmermeyer I don't think the ancient Greeks solved quadratic equations; perhaps you mean the Babylonians?
Apr 2, 2010 at 9:48 vote accept ifk
Apr 2, 2010 at 9:48 vote accept ifk
Apr 2, 2010 at 9:48
Apr 2, 2010 at 9:47 vote accept ifk
Apr 2, 2010 at 9:48
Apr 2, 2010 at 6:35 comment added KConrad I don't think Emil Artin ever wrote a book called ALGEBRA, and I think Michael Artin's book ALGEBRA is too comparatively recent to be called a classic (but maybe that just makes me look old). Since you refer to geometric algebra ideas, could you mean Emil Artin's Geometric Algebra? No, I don't think topics in there would encourage someone to want to study algebraic geometry. Maybe you mean Michael Artin's book after all.
Apr 2, 2010 at 6:24 comment added The Mathemagician LOTS of good suggestions here,KConrad.I can also suggest you look at Artin's classic ALGEBRA for more geometric algebra ideas for your students to mine.
Apr 2, 2010 at 6:19 history edited KConrad CC BY-SA 2.5
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Apr 2, 2010 at 5:55 history answered KConrad CC BY-SA 2.5