Skip to main content
Ennar's user avatar
Ennar's user avatar
Ennar's user avatar
Ennar
  • Member for 10 years, 5 months
  • Last seen this week
  • Croatia
151 votes
Accepted

Prove that the sum of pythagorean triples is always even

30 votes

Does notation ever become "easier"?

30 votes

Can we use symmetry rules in improper integrals?

26 votes

operation that is commutative but not associative

24 votes
Accepted

The confusing nature of direct sum for finite abelian groups

20 votes

The idea behind the sum of powers of 2

17 votes

How to prove that $ {\mathbf{GL}_{n}}(\mathbb{R}) $ is dense in $ {\mathbf{M}_{n}}(\mathbb{R}) $

16 votes
Accepted

Why are Desmos and W/A not plotting the graph correctly for a rational function?

15 votes
Accepted

Find the number of ways to express 1050 as sum of consecutive integers

14 votes

Complex solutions of a quintic equation: $z^5+4\overline z^3=0$

12 votes

Can I think of Algebra like this?

12 votes

How to find the orthogonal complement of a subspace?

12 votes

What is wrong with my proof by contradiction?

12 votes

Why won't a series converge if the limit of the sequence is 0?

11 votes
Accepted

What is the mathematical notation for a group of pairwise disjoint sets?

11 votes

An example of a problem which is difficult but is made easier when a diagram is drawn

10 votes

What does it mean when two Groups are isomorphic?

10 votes
Accepted

How to find $f_1\circ f_2\circ\cdots f_{13}(2),$ where $f_n(x) = \frac{nx+9}{x+3}$

10 votes
Accepted

What happens to a Matrix after moving to the other side of the equal sign?

10 votes
Accepted

Finding the smallest power of $A$ such that $A^n = I$

10 votes
Accepted

Is this diagram of the free product of two groups correct?

9 votes

Why dividing equation by absolute value gives bad result

9 votes
Accepted

Why does ${\lim_{x\to2}}\;(x-4)^x$ not exist?

9 votes

Why is "totally ordered" necessary in this implication of the Axiom of Foundation

9 votes
Accepted

Prove that $\max\{a+b,c+d\} \leq \max\{a,c\} + \max\{b,d\}$

9 votes
Accepted

How do you resist thinking about you may not be able to go further in mathematics?

9 votes

Contradiction between integration by partial fractions and substitution

8 votes

Help in proving, that $\int_{0}^{\infty} \frac{1}{\Gamma(x)} d x=e+\int_{0}^{\infty} \frac{e^{-x}}{\pi^{2}+(\ln x)^{2}} d x$ using real methods only

8 votes
Accepted

What do $x\in (1,5)$ and $x\in [1,5]$ mean?

8 votes
Accepted

Proof that $\frac{(1+\sqrt 5)^n+(1-\sqrt 5)^n}{2^n}$ is an integer

1
2 3 4 5
27