In the topic of the topology, how to determine whether or not these collections is the basis for the Eclidean topology, on R squared.(adsbygoogle = window.adsbygoogle || []).push({});

1. the collection of all open squares with sides parallel to the axes.

2. the collection of all open discs.

3. the collection of all open rectangle.

4. the collection of all open triangles.

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# Homework Help: Topology homework

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