Interactive Real Analysis - part of MathCS.org

• Real Analysis
• 1. Sets and Relations
• 2. Infinity and Induction
• 3. Sequences of Numbers
• 4. Series of Numbers
• 5. Topology
• 5.1. Open and Closed Sets
• 5.2. Compact and Perfect Sets
• 5.3. Connected and Disconnected Sets
• 6. Limits, Continuity, and Differentiation
• 7. The Integral
• 8. Sequences of Functions
• 9. Historical Tidbits
• Java Tools

Examples 5.2.5(a):

Why these ads ...

Let S = [0, 1], and C = { (-1/2, 1/2), (1/3, 2/3), (1/2, 3/2)}. Is C an open cover for S ?

Back

• C consists of open sets only.
• The union of all sets in C contains S