User Empy2

80 votes

Is every integer representable as the sum of four Fibonacci squares?

answered Jul 19 at 9:43

34 votes

Accepted

Prove there are no prime numbers in the sequence $a_n=10017,100117,1001117,10011117, \dots$

answered Mar 23, 2016 at 13:04

30 votes

Accepted

question about prime numbers

answered Nov 7, 2015 at 16:48

29 votes

Why did Euler use e to represent complex numbers?

answered Apr 13, 2015 at 19:28

27 votes

What is the limit of $x/(x+\sin x)$ as $x$ approaches infinity?

answered Jan 20, 2015 at 18:34

26 votes

A question of random points in a square and probability of intersection of their line segments

answered Nov 21 at 12:38

22 votes

Accepted

Understanding this pattern behind the Fibonacci sequence

answered Nov 5, 2014 at 12:13

21 votes

Accepted

Calculate the limit : $\lim_{x \to 0}\frac{x-\sin{x}}{x^3}$ WITHOUT using L'Hopital's rule

answered Dec 22, 2014 at 14:25

19 votes

Accepted

Check if a point is inside a rectangular shaped area (3D)?

answered Oct 9, 2015 at 15:38

16 votes

Accepted

Inequality involving square roots

answered Sep 10, 2014 at 11:47

16 votes

Accepted

Is it possible for the bisection method to provide "fake" zeros

answered Dec 1, 2018 at 16:41

15 votes

Accepted

What does $\|u\|$ mean?

answered Aug 26, 2015 at 8:06

15 votes

Intermediate digits of 34!

answered Aug 31, 2015 at 11:20

15 votes

What is the average rational number?

answered May 28, 2016 at 14:33

14 votes

If squaring a number means multiplying that number with itself then shouldn't taking square root of a number mean to divide a number by itself?

answered Jan 9, 2016 at 6:28

13 votes

Accepted

Is $x = 2$ is the only real solution for $a^x + b^x = c^x$ when $(a,b,c)$ is a pythagorean triplet?

answered Nov 16, 2014 at 11:15

13 votes

Accepted

Regular polygon of radius $1$ with diagonals: mysterious ring of radius $1/e$?

answered Dec 4, 2022 at 12:01

13 votes

Accepted

How to approximate a parameter that gives a tangent line to three circles?

answered Jan 15 at 16:00

12 votes

Accepted

Probability of getting a $7$ in Minesweeper

answered Jun 11, 2016 at 21:21

12 votes

Why do reciprocal functions work for undefined values?

answered Jul 5, 2017 at 6:30

12 votes

How would you prove that there is only a finite number of these primes?

answered Dec 28, 2017 at 15:05

12 votes

Is it true that every eigenvalue has at least one eigenvector?

answered Jun 19, 2014 at 11:05

12 votes

Sum of cubes of first n fibonacci numbers

answered Dec 5, 2014 at 15:01

11 votes

What are your favorite relations between e and pi?

answered Nov 22, 2015 at 23:52

11 votes

Calculating decimal digits by hand for extremely large numbers

answered Nov 24, 2015 at 14:57

11 votes

Expressing the trace of $A^2$ by trace of $A$

answered Sep 27, 2013 at 15:00

11 votes

If $f(x)=f(2x)$, then $f$ is differentiable

answered Jan 27, 2020 at 12:01

10 votes

Accepted

Special about 2015 with conjecture?

answered Sep 29, 2015 at 7:56

10 votes

Prove that $A_{100} \gt 14$ where $A_{n}=A_{n-1}+\frac{1}{A_{n-1}}$ and $A_1=1$

answered Jun 25, 2015 at 11:51

10 votes

Calculating $1+\frac13+\frac{1\cdot3}{3\cdot6}+\frac{1\cdot3\cdot5}{3\cdot6\cdot9}+\frac{1\cdot3\cdot5\cdot7}{3\cdot6\cdot9\cdot12}+\dots? $

answered Sep 18, 2018 at 11:03

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1,995 Answers

Is every integer representable as the sum of four Fibonacci squares?

Prove there are no prime numbers in the sequence $a_n=10017,100117,1001117,10011117, \dots$

question about prime numbers

Why did Euler use e to represent complex numbers?

What is the limit of $x/(x+\sin x)$ as $x$ approaches infinity?

A question of random points in a square and probability of intersection of their line segments

Understanding this pattern behind the Fibonacci sequence

Calculate the limit : $\lim_{x \to 0}\frac{x-\sin{x}}{x^3}$ WITHOUT using L'Hopital's rule

Check if a point is inside a rectangular shaped area (3D)?

Inequality involving square roots

Is it possible for the bisection method to provide "fake" zeros

What does $\|u\|$ mean?

Intermediate digits of 34!

What is the average rational number?

If squaring a number means multiplying that number with itself then shouldn't taking square root of a number mean to divide a number by itself?

Is $x = 2$ is the only real solution for $a^x + b^x = c^x$ when $(a,b,c)$ is a pythagorean triplet?

Regular polygon of radius $1$ with diagonals: mysterious ring of radius $1/e$?

How to approximate a parameter that gives a tangent line to three circles?

Probability of getting a $7$ in Minesweeper

Why do reciprocal functions work for undefined values?

How would you prove that there is only a finite number of these primes?

Is it true that every eigenvalue has at least one eigenvector?

Sum of cubes of first n fibonacci numbers

What are your favorite relations between e and pi?

Calculating decimal digits by hand for extremely large numbers

Expressing the trace of $A^2$ by trace of $A$

If $f(x)=f(2x)$, then $f$ is differentiable

Special about 2015 with conjecture?

Prove that $A_{100} \gt 14$ where $A_{n}=A_{n-1}+\frac{1}{A_{n-1}}$ and $A_1=1$

Calculating $1+\frac13+\frac{1\cdot3}{3\cdot6}+\frac{1\cdot3\cdot5}{3\cdot6\cdot9}+\frac{1\cdot3\cdot5\cdot7}{3\cdot6\cdot9\cdot12}+\dots? $