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#1 2015-05-12 14:49:21

mrpace
Member
Registered: 2012-08-16
Posts: 74

Which of the following are subrings of C?

Z[√7] = {a+b√7|a.b ∈ Z}

2Z+iZ = {2a+bi|a,b ∈ Z}



Where C is the complex plane, Z is the set of real integers.

Any ideas? Thanks.

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#2 2015-05-12 19:11:08

Olinguito
Member
Registered: 2014-08-12
Posts: 649

Re: Which of the following are subrings of C?

The first one.

The second one is not even a ring – it's not closed under multiplication.


Bassaricyon neblina

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