graydad

Member for 9 years, 4 months
Last seen more than 1 year ago

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calculus

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Answers

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Score Activity Newest

35

What's wrong with l'Hopital's rule?

May 17, 2015

29

What is an example of function $f: \Bbb{N} \to \Bbb{Z}$ that is a bijection?

Oct 9, 2014

19

Why/How does this sqrt term work? The inverse of a fraction in a sqrt

Mar 25, 2015

17

Easy math proofs or visual examples to make high school students enthusiastic about math

Jun 24, 2015

13

Proof: The identity matrix is invertible and the inverse of the identity is the identity

Feb 23, 2015

Questions

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8

Mary Ellen Rudin's proof that all metric space are paracompact

Sep 3, 2014

6

Prove that $\mathbb{R}^{n}-A$ with the standard topology is connected where $n \geq 2$ and $A \subset \mathbb{R}^{n}$ is countable.

Jul 31, 2014

4

Uniqueness of radix representation of integers in base 3

Jan 5, 2015

3

Show that two different representations to the base $k$ represent two different integers

Jan 13, 2015

3

Exact value of $\sum_{n=1}^\infty \frac{1}{n(n+k)(n+l)}$ for $k \in \Bbb{N}-\{0\}$ and $l \in \Bbb{N}-\{0,k\}$

Nov 16, 2014

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calculus

217

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limits

110

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48

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algebra-precalculus

90

Score

43

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real-analysis

88

Score

61

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general-topology

84

Score

62

posts

Reputation

+10

Prove a functions is injective

+10

Is $\mathbb N$ dense in $\mathbb R$?

-2

An alternative proof of the Tietze Extension Theorem(s)

+10

Let $(X ,\mathfrak T)$ be a topological space and suppose that $A$ is a subset of $X$. Then $Cl(A) = A\cup Bd(A)$. False!

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limits

Feb 2, 2018
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Mar 14, 2015
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Oct 29, 2014

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