User Mike Pierce

63 votes

8 answers

6k views

Graphs for which a calculus student can reasonably compute the arclength

asked Aug 12, 2019 at 20:13

37 votes

3 answers

4k views

When you inscribe a triangle in a circle in a triangle in a circle in a triangle ...

asked Mar 1, 2018 at 19:21

31 votes

6 answers

1k views

How do you find Pythagorean triples that approximately correspond to a right triangle with a given angle?

asked Oct 1, 2021 at 14:41

26 votes

10 answers

5k views

Why worry about commutativity but not associativity in The Fundamental Theorem of Arithmetic?

asked Apr 20, 2018 at 19:13

19 votes

3 answers

3k views

"Drawable" Examples of Vector Bundles

asked Dec 13, 2014 at 0:45

13 votes

2 answers

2k views

Is a trigonometric function applied to a rational multiple of $\pi$ always algebraic? [duplicate]

asked Oct 22, 2014 at 18:02

12 votes

2 answers

854 views

Exercises to help a student become accustomed to Sweedler notation

asked Nov 28, 2017 at 17:49

11 votes

1 answer

523 views

Integration technique of writing $\int_0^{\infty}$ as $\int_0^1 + \int_1^{\infty}$ and using the substitution $\frac{1}{x} \leftrightarrow u$

asked Dec 15, 2016 at 17:33

10 votes

3 answers

587 views

Over a commutative unital ring, does $\det A = 0$ imply that $A\mathbf{x} = 0$ has a non-zero solution?

asked Aug 10, 2018 at 15:20

10 votes

1 answer

509 views

Is there a natural way to regard a valued quiver as a category?

asked Nov 20, 2018 at 18:24

9 votes

2 answers

191 views

Reference for Kaplansky's proof that in $\mathbb{C}[G]$, $ab=1$ implies $ba=1$

asked Aug 6, 2018 at 21:13

9 votes

1 answer

236 views

Does inscribing a circle, then a triangle, then ..., inside of an initial triangle telescope to some "center" of that triangle?

asked Apr 25, 2018 at 15:44

9 votes

1 answer

309 views

For which categories is its Yoneda embedding essentially surjective?

asked Jan 9, 2020 at 14:59

8 votes

1 answer

19k views

Showing a function has exactly one zero with IVT and Rolle's Theorem

asked Mar 9, 2018 at 4:52

8 votes

1 answer

983 views

Multiple choice exam where no two consecutive answers are the same (2)

asked Jan 23, 2017 at 19:40

8 votes

1 answer

173 views

Looking for a Resource to Identify/Name a Given Graph

asked Sep 10, 2015 at 7:18

7 votes

2 answers

545 views

Significance of adjoint relationship with Ext instead of Hom

asked Feb 19, 2018 at 16:53

6 votes

2 answers

445 views

Peirce decomposition of a ring: must the ideal generators be idempotent in characteristic 2?

asked Aug 4, 2018 at 19:15

6 votes

3 answers

349 views

How much longer does it take to paint a similar box with $5$ times more volume?

asked Nov 5, 2018 at 18:27

6 votes

2 answers

474 views

A finitely-generated ring over the integers modulo a max ideal is necessarily a finite field

asked May 11, 2018 at 15:14

5 votes

4 answers

4k views

The support of a sheaf is not necessarily closed

asked Sep 5, 2017 at 17:46

5 votes

2 answers

2k views

Example of a Tensor Product of Modules with Non-Decomposable Elements

asked Feb 8, 2016 at 6:41

5 votes

1 answer

223 views

What's the term to describe a morphism that isn't a composite of morphisms?

asked Nov 27, 2018 at 22:42

5 votes

2 answers

335 views

How do you explain why the arguments of $\operatorname{Ext}^1(A,B)$ aren't "backwards"?

asked Feb 23, 2019 at 21:55

5 votes

0 answers

224 views

What are are some illustrative (non-)examples of proper morphisms?

asked Jan 9, 2020 at 14:57

5 votes

1 answer

51 views

Is there meaning in the minimal instances of a variable you need to write a rational expression?

asked Sep 24, 2020 at 17:34

5 votes

1 answer

194 views

How can we think of the codomain (range) of a probability density function?

asked Jul 16, 2021 at 18:28

5 votes

1 answer

349 views

What's the minimum number of keystrokes needed to type n asterisks?

asked Jul 28, 2021 at 23:44

4 votes

2 answers

273 views

What are the sine and cosine of dyadic angles?

asked Oct 3, 2021 at 21:12

4 votes

2 answers

92 views

Can you describe all the ways to "un-localize" a ring?

asked Oct 17, 2019 at 15:30

Stack Exchange Network

108 Questions

Graphs for which a calculus student can reasonably compute the arclength

When you inscribe a triangle in a circle in a triangle in a circle in a triangle ...

How do you find Pythagorean triples that approximately correspond to a right triangle with a given angle?

Why worry about commutativity but not associativity in The Fundamental Theorem of Arithmetic?

"Drawable" Examples of Vector Bundles

Is a trigonometric function applied to a rational multiple of $\pi$ always algebraic? [duplicate]

Exercises to help a student become accustomed to Sweedler notation

Integration technique of writing $\int_0^{\infty}$ as $\int_0^1 + \int_1^{\infty}$ and using the substitution $\frac{1}{x} \leftrightarrow u$

Over a commutative unital ring, does $\det A = 0$ imply that $A\mathbf{x} = 0$ has a non-zero solution?

Is there a natural way to regard a valued quiver as a category?

Reference for Kaplansky's proof that in $\mathbb{C}[G]$, $ab=1$ implies $ba=1$

Does inscribing a circle, then a triangle, then ..., inside of an initial triangle telescope to some "center" of that triangle?

For which categories is its Yoneda embedding essentially surjective?

Showing a function has exactly one zero with IVT and Rolle's Theorem

Multiple choice exam where no two consecutive answers are the same (2)

Looking for a Resource to Identify/Name a Given Graph

Significance of adjoint relationship with Ext instead of Hom

Peirce decomposition of a ring: must the ideal generators be idempotent in characteristic 2?

How much longer does it take to paint a similar box with $5$ times more volume?

A finitely-generated ring over the integers modulo a max ideal is necessarily a finite field

The support of a sheaf is not necessarily closed

Example of a Tensor Product of Modules with Non-Decomposable Elements

What's the term to describe a morphism that isn't a composite of morphisms?

How do you explain why the arguments of $\operatorname{Ext}^1(A,B)$ aren't "backwards"?

What are are some illustrative (non-)examples of proper morphisms?

Is there meaning in the minimal instances of a variable you need to write a rational expression?

How can we think of the codomain (range) of a probability density function?

What's the minimum number of keystrokes needed to type n asterisks?

What are the sine and cosine of dyadic angles?

Can you describe all the ways to "un-localize" a ring?