User Adriano

99 votes

Prove that every group of order $4$ is abelian

answered Jul 14, 2013 at 20:54

76 votes

Accepted

What would have been our number system if humans had more than 10 fingers? Try to solve this puzzle.

answered Aug 6, 2013 at 0:46

62 votes

Accepted

Prove that $\log _5 7 < \sqrt 2.$

answered Jun 18, 2013 at 5:21

55 votes

Accepted

Bayes rule with multiple conditions

answered Jun 1, 2013 at 22:11

41 votes

Accepted

A finite set always has a maximum and a minimum.

answered Nov 2, 2013 at 9:18

31 votes

Accepted

Do equal bases imply equal powers?

answered Sep 2, 2013 at 20:03

28 votes

The meaning of notation like $f\colon \mathbb R^2 \to \mathbb R$, $x \in \mathbb R^n$, and $x \in \mathbb R$.

answered Jan 6, 2015 at 6:31

19 votes

Accepted

Proof that any linear system cannot have exactly 2 solutions.

answered Sep 16, 2015 at 21:54

18 votes

Prove that the additive inverse of an odd integer is an odd integer

answered Jun 23, 2013 at 1:06

16 votes

Accepted

Prove that the graph is connected

answered May 4, 2015 at 0:45

14 votes

Mantel's Theorem proof verification

answered Jan 6, 2014 at 9:22

13 votes

Accepted

Help Evaluating $\lim_{x \to \infty} \sqrt{x + \sqrt{x + \sqrt{x}}} - \sqrt{x}$

answered Jun 15, 2014 at 1:42

13 votes

Why is this limit statement false?

answered Sep 9, 2014 at 22:49

13 votes

Accepted

How to integrate $\int \frac{1}{\cos(x)}\,\mathrm dx$

answered Jun 13, 2013 at 7:59

12 votes

Which law of logical equivalence says $P\Leftrightarrow Q ≡ (P\lor Q) \Rightarrow(P\land Q)$

answered May 21, 2013 at 1:26

12 votes

Accepted

How many numbers can be formed using digits 1 2 3 4 5 6 7 8 9 such that they are in increasing order(e.g. 12345, 578)?

answered Aug 26, 2013 at 9:08

12 votes

Accepted

Isosceles triangle has the least perimeter among triangles on the same base with same area?

answered Aug 10, 2015 at 17:35

12 votes

Accepted

Proof of Inequality using AM-GM

answered Nov 17, 2014 at 7:49

11 votes

Accepted

Prove $s$ is a supremum iff for all $\epsilon>0$ there exists $a\in A$ such that $a>s-\epsilon$.

answered Feb 13, 2015 at 17:55

11 votes

For what natural numbers is $n^3 < 2^n$? Prove by induction

answered Jul 20, 2013 at 7:34

11 votes

Accepted

How to evaluate $\displaystyle \lim_{x \to \infty}\frac{8-\sqrt{x}}{8+\sqrt{x}}$

answered Sep 9, 2014 at 5:33

10 votes

Solve an equation with $e^{(x-2)}=e^{4}\cdot e^{\sqrt{x}}$

answered Jun 22, 2013 at 10:46

10 votes

Accepted

Show that any continuous $f:[0,1] \rightarrow [0,1]$ has a fixed point $\zeta$

answered Jun 20, 2013 at 1:28

10 votes

Accepted

Cube root of a binomial

answered Sep 21, 2016 at 3:10

10 votes

Accepted

Write $1681$ using four $4$s

answered Oct 2, 2014 at 22:04

10 votes

Accepted

Is it possible to express disjunction through conjunction and implication?

answered Jun 2, 2019 at 18:57

9 votes

Accepted

If $n\ge m$, then the number of $m$-cycles in $S_n$ is given by $\frac{n(n-1)(n-2)\cdots(n-m+1)}{m}$.

answered Oct 9, 2014 at 18:58

9 votes

Accepted

Curves with a common tangent line

answered Nov 10, 2014 at 22:16

9 votes

Accepted

Formula for the angle of a line $y = mx$ as a function of $m$.

answered Nov 13, 2014 at 19:34

9 votes

Confusing definition of limit points

answered Mar 20, 2016 at 8:01

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1,382 Answers

Prove that every group of order $4$ is abelian

What would have been our number system if humans had more than 10 fingers? Try to solve this puzzle.

Prove that $\log _5 7 < \sqrt 2.$

Bayes rule with multiple conditions

A finite set always has a maximum and a minimum.

Do equal bases imply equal powers?

The meaning of notation like $f\colon \mathbb R^2 \to \mathbb R$, $x \in \mathbb R^n$, and $x \in \mathbb R$.

Proof that any linear system cannot have exactly 2 solutions.

Prove that the additive inverse of an odd integer is an odd integer

Prove that the graph is connected

Mantel's Theorem proof verification

Help Evaluating $\lim_{x \to \infty} \sqrt{x + \sqrt{x + \sqrt{x}}} - \sqrt{x}$

Why is this limit statement false?

How to integrate $\int \frac{1}{\cos(x)}\,\mathrm dx$

Which law of logical equivalence says $P\Leftrightarrow Q ≡ (P\lor Q) \Rightarrow(P\land Q)$

How many numbers can be formed using digits 1 2 3 4 5 6 7 8 9 such that they are in increasing order(e.g. 12345, 578)?

Isosceles triangle has the least perimeter among triangles on the same base with same area?

Proof of Inequality using AM-GM

Prove $s$ is a supremum iff for all $\epsilon>0$ there exists $a\in A$ such that $a>s-\epsilon$.

For what natural numbers is $n^3 < 2^n$? Prove by induction

How to evaluate $\displaystyle \lim_{x \to \infty}\frac{8-\sqrt{x}}{8+\sqrt{x}}$

Solve an equation with $e^{(x-2)}=e^{4}\cdot e^{\sqrt{x}}$

Show that any continuous $f:[0,1] \rightarrow [0,1]$ has a fixed point $\zeta$

Cube root of a binomial

Write $1681$ using four $4$s

Is it possible to express disjunction through conjunction and implication?

If $n\ge m$, then the number of $m$-cycles in $S_n$ is given by $\frac{n(n-1)(n-2)\cdots(n-m+1)}{m}$.

Curves with a common tangent line

Formula for the angle of a line $y = mx$ as a function of $m$.

Confusing definition of limit points