User Justin L. - Mathematics Stack Exchange

bio	website	janineweshould.com
	location	Irvine, CA
	age	22
visits	member for	2 years, 10 months
	seen	May 8 at 22:59
stats	profile views	710

	3,877 reputation	bio	website	janineweshould.com	visits	member for	2 years, 10 months
12344 badges		location	Irvine, CA		seen	May 8 at 22:59

18

43

votes

12

answers

3

kviews

Conjectures that have been disproved with extremely large counterexamples?

apr 18 at 21:31 Joe K 121

14

36

votes

3

answers

5

kviews

Logic problem: Identifying poisoned wines out of a sample, minimizing test subjects with constraints

puzzle recreational-mathematics

may 6 at 14:00 user76396 11

8

18

votes

8

answers

4

kviews

Why is “the set of all sets” a paradox?

paradox logic set-theory

nov 23 at 3:39 Asaf Karagila 91.3k

13

17

votes

14

answers

3

kviews

Intuitive understanding of the derivatives of $\sin x$ and $\cos x$

calculus trigonometry

aug 16 at 22:37 Peter Tamaroff 25.9k

3

17

votes

9

answers

3

kviews

Is there possibly a largest prime number?

number-theory prime-numbers

sep 8 '11 at 2:49 Community♦ 1

3

13

votes

2

answers

823

views

Why is the decimal representation of 1/7 “cyclical”?

number-theory fractions decimal-expansion

dec 12 '11 at 15:20 J. M. 38.9k

2

12

votes

1

answer

5

kviews

How many circles of a given radius can be packed into a given rectangular box?

geometry packing-problem

aug 7 '11 at 18:41 J. M. 38.9k

3

11

votes

1

answer

334

views

Why does the log-log scale on my Slide Rule work?

intuition

feb 29 '12 at 8:37 Community♦ 1

2

10

votes

1

answer

299

views

What property of certain regular polygons allows them to be faces of the Platonic Solids?

geometry polyhedra

dec 12 '11 at 12:21 J. M. 38.9k

3

10

votes

5

answers

439

views

Why does this process, when iterated, tend towards a certain number? (the golden ratio?)

limit convergence

may 13 '11 at 11:35 J. M. 38.9k

1

9

votes

2

answers

823

views

Finding Moment of Inertia (rotional inertia?) $I$ using integration?

calculus physics

nov 9 '10 at 8:17 Casebash 3,517

1

8

votes

4

answers

1

kviews

Are there any functions that are (always) continuous yet not differentiable? Or vice-versa?

real-analysis

feb 23 '11 at 6:27 Community♦ 1

2

8

votes

8

answers

1

kviews

What is larger — the set of all positive even numbers, or the set of all positive integers?

set-theory infinity

aug 2 '10 at 17:06 David Lewis 1,080

7

votes

4

answers

550

views

Why is the matrix-defined Cross Product of two 3D vectors always orthogonal?

linear-algebra

nov 23 '11 at 2:24 badp 542

1

7

votes

6

answers

2

kviews

What does it mean to be going 40 mph (or 64 kph, etc.) at a given moment?

calculus intuition

may 31 '11 at 13:11 GEdgar 19k

1

6

votes

11

answers

5

kviews

Derivation of the formula for the vertex of a Parabola

algebra-precalculus plane-curves conic-sections

apr 24 at 21:08 Roberto 11

6

votes

7

answers

2

kviews

Why are the differences between consecutive squares equal to the sequence of odd numbers?

elementary-number-theory

mar 9 at 7:46 Martin Sleziak 20.3k

1

5

votes

4

answers

7

kviews

When you randomly shuffle a deck of cards, what is the probability that it is a unique permutation never before configured?

probability-theory

mar 13 at 15:19 Ted Grant 1

3

5

votes

4

answers

754

views

Intuitive reasoning behind the Chain Rule in multiple variables?

calculus linear-algebra

mar 26 '12 at 17:59 Arturo Magidin 158k

5

votes

2

answers

5

kviews

Compass-and-straightedge construction of the square root of a given line?

geometry euclidean-geometry geometric-construction

dec 23 '11 at 6:07 J. M. 38.9k

5

votes

2

answers

167

views

Question about the nature of coordinate systems

linear-algebra coordinate-systems

aug 31 '11 at 23:31 Tanner Swett 661

1

5

votes

2

answers

568

views

Generalizations of the number theory concepts of “even” and “odd”?

number-theory parity

jan 6 '11 at 22:36 Justin L. 3,877

2

4

votes

1

answer

2

kviews

Probability of a point taken from a certain normal distribution will be greater than a point taken from another?

probability normal-distribution

may 20 '11 at 9:21 Shai Covo 17k

4

votes

5

answers

2

kviews

Can non-linear transformations be represented as Transformation Matrices?

linear-algebra transformation

sep 9 '10 at 23:00 J. M. 38.9k

3

votes

4

answers

168

views

Given a metric function between a set of abstract points, what is the best way to plot them on a 2D space?

metric-spaces

feb 1 at 17:22 Community♦ 1

3

votes

2

answers

231

views

Why are only singly and doubly ruled non-planar surfaces found? Why not triply ruled?

geometry

jun 13 '11 at 7:54 Matt E 58.1k

2

votes

1

answer

233

views

Is this parametric curve space-filling? Why or why not?

functions

mar 2 '11 at 18:28 Justin L. 3,877

1

vote

1

answer

386

views

Using differential equations to graph velocity over time of a falling object subject to wind resistance

calculus physics differential-equations

jun 24 '12 at 1:58 Arturo Magidin 158k

1

vote

2

answers

176

views

If I wanted something to decay with a half-life of $n$ days, what should I multiply it by every day?

algebra-precalculus

dec 9 '10 at 4:50 Arturo Magidin 158k

1

vote

3

answers

516

views

Geometric interpretation of the multiplication of complex numbers?

ring-theory complex-numbers vector-spaces

oct 16 '10 at 1:22 I. J. Kennedy 1,267

Justin L.

32 Questions