Joe Johnson 126

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148 Answers

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18	Prove that $A=\left(\begin{array}{ccc}1&2&3\\4&5&6\\7&8&9\end{array}\right)$ is not invertible
17	Funny identities
16	Real life applications of Topology
10	Can every closed subset of real numbers be written as the countable (or finite) union of disjoint closed intervals?
9	Decide for which positive values on a that makes the series converge

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5,482 Reputation

+10	Real life applications of Topology
+15	Proof involving homogeneous system of linear equations with det 0.
+10	Why is cofiniteness included in the definition of direct sum of submodules?
+10	general topology exercise 777

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32 Questions

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23	Do We Need the Digits of $\pi$?
9	A Book of Neat Theorems for Laymen
8	Some Good Algebraic Topology Exercises
7	Poincare Duality Reference
7	The Power of Taylor Series

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104 Tags

75 homework × 23	31 general-topology × 7
54 calculus × 28	25 real-analysis × 10
45 linear-algebra × 15	25 soft-question × 6
38 abstract-algebra × 15	24 algebra-precalculus × 7
32 algebraic-topology × 21	24 matrices × 4

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