- #1

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I wanna show that [itex]IJ=I \cap J[/itex] and one direction is trivial. But proving [itex]I \cap J \subset IJ[/itex] has stumped me so far. Anyone have any ideas?

- Thread starter camilus
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- #1

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I wanna show that [itex]IJ=I \cap J[/itex] and one direction is trivial. But proving [itex]I \cap J \subset IJ[/itex] has stumped me so far. Anyone have any ideas?

- #2

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K is an algebraically closed field, of course.

- #3

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- #4

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So this approach won't work. I want to show just this case, not prove the general statement of when the intersection of two ideals in poly ring is equal to their product.

I just need and argument for I intersect J \subset IJ for this particular case (I already know it is true, I just need to show it).

Thanks anyways micromass

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- #6

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The question is what we do from there.

We know that g(0,0,z,t)=0 (because g in I) hence g(0,0,z,t)=zg'(0,0,z,t)-tg"(0,0,z,t)=0.

But from here can we conclude that g',g" are in I? I don't see how to do it..

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