User sizz - Mathematics Stack Exchange

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	2,265 reputation	bio	website		visits	member for	1 year, 2 months
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1

13

votes

1

answer

203

views

Spivak's proof on “hard theorems”

may 5 at 20:52 sizz 2,265

5

9

votes

7

answers

470

views

Can someone show me why this factorization is true?

algebra-precalculus factoring

dec 17 at 4:01 Steven Stadnicki 14.2k

1

8

votes

3

answers

252

views

Showing that $\max\{f+g\} \leq \max f + \max g$

algebra-precalculus

mar 10 at 20:28 Maisam Hedyelloo 3,290

1

7

votes

1

answer

199

views

Understanding a proof in Spivak

calculus real-analysis

jan 11 at 2:24 sizz 2,265

2

7

votes

4

answers

299

views

Converge or Diverge? Show that $\sum_{n=1}^{\infty} \frac{1}{n^{{n}/{\log(n)}}}$ converges

sequences-and-series

jun 18 '12 at 9:33 Chris's wise sister 11.5k

6

votes

3

answers

187

views

What's the reason why this sequence of function doesn't converge uniformly to $f$?

real-analysis sequences-and-series

jan 7 at 11:41 Haskell Curry 11.1k

5

votes

2

answers

105

views

Is this sloppy writing for limits?

multivariable-calculus proof-writing

feb 6 at 2:27 user49685 550

5

votes

4

answers

277

views

Can open sets be an open cover, for itself?

real-analysis general-topology definition

jan 5 at 0:46 amWhy 54.1k

2

5

votes

3

answers

363

views

Could someone remind me why is incorrect to switch an infinite sum and an integral?

calculus real-analysis measure-theory

jul 6 at 20:24 ncmathsadist 17.1k

4

votes

7

answers

274

views

How does this sum go to $0$?

sequences-and-series limit

may 17 at 6:11 Mhenni Benghorbal 13.9k

4

votes

3

answers

71

views

Extreme Value Theorem Proof (SPIVAK)

calculus proof-strategy

may 8 at 1:41 anorton 3,857

4

votes

1

answer

62

views

How does one DERIVE the formula for the maximum of two numbers

proof-strategy

may 6 at 2:04 Alex L 329

4

votes

2

answers

106

views

A proof in Spivak on integration.

calculus

mar 10 at 22:23 kahen 8,054

4

votes

1

answer

108

views

$A$ square matrix,nonsingular $\implies $ all submatrixes of $A$ are also nonsingular?

linear-algebra matrices examples-counterexamples

mar 2 at 12:22 Git Gud 5,740

4

votes

3

answers

100

views

Is there a counterexample to the claim that if $\mathbf y\cdot\mathbf y=1$ and $\mathbf x\cdot\mathbf y=c$ then $\mathbf x=c\mathbf y$?

linear-algebra multivariable-calculus vector-analysis

feb 3 at 2:10 Muphrid 3,369

2

4

votes

1

answer

90

views

Incomplete metric space.

real-analysis

jan 27 at 3:56 copper.hat 28.4k

4

votes

3

answers

191

views

Variation of Parameters Differential Equations Derivation

differential-equations

dec 23 at 17:07 oen 7,433

4

votes

2

answers

150

views

The Maximum possible order for an element $S_n$

abstract-algebra

nov 7 at 4:08 Charles Boyd 442

1

4

votes

2

answers

118

views

Independent events and Dependent events

probability

jul 22 at 18:15 André Nicolas 160k

1

4

votes

2

answers

123

views

Can I apply Fundamental Theorem of Calculus here?

calculus integral

jul 3 at 7:50 Jyrki Lahtonen 30.6k

3

votes

5

answers

144

views

$\sup (A+B) = \sup A + \sup B$

real-analysis

may 9 at 12:31 Cameron Buie 27.3k

3

votes

2

answers

81

views

An almost upper bound. Is this a counter example? (SPIVAK)

calculus real-analysis

may 8 at 20:13 sizz 2,265

3

votes

2

answers

49

views

Upper and lower sums - Spivak

calculus

apr 3 at 18:19 copper.hat 28.4k

1

3

votes

2

answers

181

views

Did I underestimate the limit proof?

sequences-and-series limit proof-strategy

mar 29 at 0:53 Aryabhata 47.5k

3

votes

1

answer

78

views

Calculus exercise - differentiability and $C^1$ functions

real-analysis

feb 6 at 0:46 julien 22.5k

3

votes

2

answers

108

views

Finding $\lim\limits_{(x,y) \to (0,0)} \frac{|xy|}{\sqrt{x^2 + y^2}}$

limit multivariable-calculus

feb 5 at 23:09 Joe 3,060

3

votes

4

answers

122

views

Understanding a proof in Rudin

real-analysis general-topology

jan 1 at 4:13 amWhy 54.1k

3

votes

2

answers

138

views

Why does this limit exist and this function continuous?

calculus

dec 24 at 21:02 amWhy 54.1k

1

3

votes

2

answers

294

views

Improper use of Stokes and Divergence Theorem. Find the problem

calculus multivariable-calculus

dec 23 at 2:16 Jesse Madnick 7,881

1

3

votes

3

answers

188

views

Interesting GRE problem

algebra-precalculus

dec 21 at 22:03 Brian Rushton 1,351

sizz

228 Questions