User daniel.jackson - Mathematics Stack Exchange

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	1,026 reputation	bio	website		visits	member for	2 years, 6 months
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2

6

votes

3

answers

756

views

Spectral decomposition of a normal matrix

linear-algebra spectral-theory

mar 21 at 18:40 Amos Ong 1

5

votes

3

answers

598

views

Question regarding Weierstrass M-test

real-analysis sequences-and-series

may 13 '12 at 10:54 J. M. 38.8k

10

votes

2

answers

334

views

If $(a_{n})$ is increasing, is $u_{n}=\frac{a_{1}+\cdots+a_{n}}{n}$ increasing as well?

calculus homework sequences-and-series

apr 27 '12 at 2:10 Daniela del Carmen 599

1

vote

2

answers

125

views

Maximizing rectangle area without intersecting others

geometry

apr 17 '12 at 22:11 Joseph O'Rourke 6,100

1

vote

1

answer

48

views

Depending on variable to calculate joint distribution

probability

feb 22 '12 at 22:32 David Mitra 40.9k

3

10

votes

6

answers

588

views

Given $a_{1}=1, \ a_{n+1}=a_{n}+\frac{1}{a_{n}}$, find $\lim \limits_{n\to\infty}\frac{a_{n}}{n}$

calculus sequences-and-series homework

nov 13 '11 at 16:03 Quixotic 7,920

4

votes

1

answer

278

views

Does $\sum \limits_{n=1}^{\infty} \frac{1}{\ln(n^n+n^2)}$ converge?

calculus homework sequences-and-series

nov 13 '11 at 15:57 Quixotic 7,920

1

vote

2

answers

374

views

Convergence of $\sum \limits_{n=1}^{\infty} (1-\frac{\sin a_{n}}{a_{n}})$ when $\sum \limits_{n=1}^{\infty} a_{n}$ converges

calculus homework sequences-and-series

nov 13 '11 at 15:51 Quixotic 7,920

4

9

votes

2

answers

667

views

Does $\sum \limits_{n=1}^\infty\frac{\sin n}{n}(1+\frac{1}{2}+\cdots+\frac{1}{n})$ converge (absolutely)?

calculus sequences-and-series

nov 13 '11 at 15:49 Quixotic 7,920

1

vote

1

answer

196

views

Maximal subspace that a quadratic form is non-negative on

linear-algebra quadratic-forms

jul 10 '11 at 11:00 wildildildlife 2,840

1

4

votes

4

answers

237

views

if $A^2 \in M_{3}(\mathbb{R})$ is diagonalizable then so is $A$

linear-algebra

jul 6 '11 at 19:37 Mark Schwarzmann 1,867

2

3

votes

3

answers

205

views

Confused about quadratic forms

linear-algebra quadratic-forms

jul 5 '11 at 4:11 André Nicolas 160k

1

vote

2

answers

40

views

Finding $a_n$ using a given matrix

linear-algebra

jun 23 '11 at 12:43 ncmathsadist 16.9k

5

votes

2

answers

211

views

If every eigenvector of $T$ is also an eigenvector of $T^{*}$ then $T$ is a normal operator

linear-algebra

jun 17 '11 at 15:40 Arturo Magidin 158k

2

votes

2

answers

388

views

Non diagonalizable matrix

linear-algebra

jun 4 '11 at 21:41 Aaron 6,642

1

vote

2

answers

121

views

Positive semidefinite quadratic form

linear-algebra

may 28 '11 at 17:12 daniel.jackson 1,026

1

vote

1

answer

1

kviews

Multiplication of block matrices

linear-algebra

mar 31 '11 at 16:09 hardmath 7,019

2

3

votes

3

answers

440

views

Adjoint of a linear transformation in an infinite dimension inner product space

linear-algebra

mar 26 '11 at 19:09 Qiaochu Yuan 117k

0

votes

1

answer

407

views

Conjugate-transpose of a linear transformation

homework linear-algebra

mar 25 '11 at 15:15 joriki 92.1k

4

votes

2

answers

123

views

Regarding orthonormal basis

linear-algebra

mar 14 '11 at 12:45 daniel.jackson 1,026

4

votes

1

answer

197

views

Show $\int_{0}^{\infty}\sin(f(x))dx$ converges if $\int_{0}^{\infty}f(x)dx$ converges and $f(x)$ is a decreasing, continuous function in $[0, \infty)$

calculus improper-integrals

feb 3 '11 at 19:37 Zarrax 19.7k

2

votes

4

answers

334

views

Example of discontinuous $u(x)$ where $\sum u_{n}(x)\to u(x)$ uniformly in $I \subset \mathbb{R}$

calculus sequences-and-series

jan 31 '11 at 22:52 kahen 8,054

2

votes

1

answer

230

views

One-sided limits of a uniformly convergent function sequence and its limit function

real-analysis homework

jan 17 '11 at 20:56 Nate Eldredge 22.3k

1

4

votes

1

answer

157

views

Show that there's a bijective $f: \mathbb{N} \to \mathbb{N}$ such that $\sum_{n=1}^{\infty} (-1)^{f(n)}\ln\frac{f(n)+1}{f(n)}=\ln 2010$

calculus homework sequences-and-series

jan 7 '11 at 15:10 Prometheus 2,872

2

votes

1

answer

206

views

Bounding a series from above using the integral test

calculus sequences-and-series integral

jan 5 '11 at 20:26 Isaac 21.1k

6

votes

1

answer

110

views

Why is the remainder function $R_{n}(x)$ decreasing?

calculus sequences-and-series taylor-expansion

dec 22 '10 at 0:17 T.. 8,083

3

9

votes

1

answer

391

views

Basic Taylor expansion question

calculus taylor-expansion

dec 20 '10 at 4:59 Arturo Magidin 158k

2

votes

3

answers

478

views

Mean value theorem and a strictly increasing, positive second derivative

calculus homework taylor-expansion

dec 18 '10 at 8:33 Christian Blatter 32.3k

4

votes

1

answer

202

views

Diverging improper integral

calculus improper-integrals

dec 10 '10 at 14:43 Willie Wong♦ 30.6k

2

votes

1

answer

208

views

Show $\int_{0}^{\infty}f(x^2)dx$ exists if $f(x)$ is continuous and $\forall a\gt 0, |\int_{0}^{a}f(x)dx| \leq M$

calculus homework integral

dec 7 '10 at 20:44 Shai Covo 16.9k

daniel.jackson

37 Questions