User Isaac

25 votes

15 answers

8k views

Useful examples of pathological functions

asked Jul 26, 2010 at 21:35

24 votes

3 answers

8k views

Circular permutations with indistinguishable objects

asked Jul 23, 2010 at 18:14

21 votes

2 answers

5k views

What is the best way to solve an equation involving multiple absolute values?

asked Aug 23, 2010 at 22:00

21 votes

3 answers

3k views

Birthday-coverage problem

asked Mar 13, 2011 at 20:13

34 votes

2 answers

17k views

Probability that a stick randomly broken in two places can form a triangle

asked Jul 25, 2010 at 5:31

73 votes

10 answers

48k views

Proving that $1$- and $2D$ simple symmetric random walks return to the origin with probability $1$

asked Jul 23, 2010 at 4:05

66 votes

12 answers

86k views

Sum of the alternating harmonic series $\sum_{k=1}^{\infty}\frac{(-1)^{k+1}}{k} = \frac{1}{1} - \frac{1}{2} + \cdots $

asked Jul 26, 2010 at 8:38

5 votes

1 answer

3k views

Proving the Shoelace Method at the Precalculus Level

asked Jul 28, 2010 at 18:26

6 votes

5 answers

2k views

Least wasteful use of stamps to achieve a given postage

asked Jul 26, 2010 at 21:48

12 votes

4 answers

892 views

Describe the locus in the complex plane of the zeros of a quartic polynomial as the constant term varies

asked Jul 23, 2010 at 3:59

21 votes

1 answer

170k views

Solving Triangles (finding missing sides/angles given 3 sides/angles)

asked Feb 7, 2012 at 3:31

5 votes

4 answers

1k views

What transformations of the plane are geometrically constructable (compass & straight edge)?

asked Jul 23, 2010 at 18:40

5 votes

6 answers

4k views

Why, conceptually, do limaçons $r=a+b\cos\theta$ have dimples when $|\frac{a}{b}|<2$?

asked Oct 9, 2011 at 17:49

45 votes

7 answers

3k views

Bad Fraction Reduction That Actually Works

asked Jul 5, 2011 at 18:27

7 votes

5 answers

3k views

Usefulness of Conic Sections

asked Jul 28, 2010 at 18:36

16 votes

4 answers

12k views

Is "locally linear" an appropriate description of a differentiable function?

asked Oct 21, 2010 at 19:11

15 votes

1 answer

2k views

What is the standard interpretation of order of operations for the basic arithmetic operations?

asked May 1, 2011 at 20:35

36 votes

11 answers

16k views

Mandelbrot-like sets for functions other than $f(z)=z^2+c$?

asked Jul 29, 2010 at 2:57

3 votes

1 answer

173 views

Solving inequalities comparing $f(x)$ to $0$ where $f$ is an elementary function

asked May 1, 2011 at 20:19

5 votes

3 answers

2k views

How to determine arc measures from angles between secant and tangents (without trigonometry)

asked Dec 8, 2010 at 3:03

Stack Exchange Network

20 Questions

Useful examples of pathological functions

Circular permutations with indistinguishable objects

What is the best way to solve an equation involving multiple absolute values?

Birthday-coverage problem

Probability that a stick randomly broken in two places can form a triangle

Proving that $1$- and $2D$ simple symmetric random walks return to the origin with probability $1$

Sum of the alternating harmonic series $\sum_{k=1}^{\infty}\frac{(-1)^{k+1}}{k} = \frac{1}{1} - \frac{1}{2} + \cdots $

Proving the Shoelace Method at the Precalculus Level

Least wasteful use of stamps to achieve a given postage

Describe the locus in the complex plane of the zeros of a quartic polynomial as the constant term varies

Solving Triangles (finding missing sides/angles given 3 sides/angles)

What transformations of the plane are geometrically constructable (compass & straight edge)?

Why, conceptually, do limaçons $r=a+b\cos\theta$ have dimples when $|\frac{a}{b}|<2$?

Bad Fraction Reduction That Actually Works

Usefulness of Conic Sections

Is "locally linear" an appropriate description of a differentiable function?

What is the standard interpretation of order of operations for the basic arithmetic operations?

Mandelbrot-like sets for functions other than $f(z)=z^2+c$?

Solving inequalities comparing $f(x)$ to $0$ where $f$ is an elementary function

How to determine arc measures from angles between secant and tangents (without trigonometry)