User agha

16 votes

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Does it follow that $(n!)^n$ divide $(n^2)!$

answered Feb 4, 2015 at 21:46

15 votes

Are set differences in a sigma algebra?

answered Dec 30, 2014 at 23:00

14 votes

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Sum of the squares of numbers

answered Feb 28, 2015 at 20:26

13 votes

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Example of algebra that is not a $\sigma$-algebra

answered Nov 7, 2014 at 16:21

12 votes

How do I solve $y' = \sin(x - y)$?

answered Jul 14, 2014 at 21:45

11 votes

Fibonacci Numbers Proof: $ f_n = \binom n0 + \binom{n-1}1 +\dots+ \binom{n-k}k$

answered Jul 7, 2014 at 19:32

10 votes

Converting recursive equations into matrices

answered Jul 6, 2014 at 20:34

9 votes

Asymptotic behaviour of the integral of the quadratic mean of the coordinates on the hypercube

answered Jul 6, 2014 at 21:22

9 votes

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If in an inner product space $\langle x,u\rangle=\langle x,v\rangle$ for all $x$, show that $u=v$.

answered Oct 7, 2014 at 14:00

8 votes

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Prove that there are infinitely many integer solutions to a diophantine equation

answered Sep 30, 2014 at 17:34

8 votes

How can the equation $e^{-x^{2}}-2x^2e^{-x^{2}}=0$ be solved

answered Oct 26, 2014 at 21:30

7 votes

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Using l'Hôpital rule to find $\lim_{x\to-\infty} xe^x$

answered Jul 19, 2014 at 19:04

7 votes

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Is the preimage of a bounded set also bounded?

answered Dec 19, 2014 at 16:44

7 votes

Solve logarithmic equation for $x$ to find the inverse of $f(x)= \ln(x+\sqrt{x^2+1})$

answered Jan 5, 2015 at 23:09

7 votes

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$p,q,r$ primes, $\sqrt{p}+\sqrt{q}+\sqrt{r}$ is irrational.

answered Aug 4, 2015 at 19:46

6 votes

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Integrate a power of logarithm

answered Feb 25, 2015 at 15:12

6 votes

How can I calculate the total number of possible anagrams for a set of letters?

answered Jul 23, 2014 at 22:23

6 votes

Closure of $[1, 2] \cup [4, 5]$

answered Jun 30, 2014 at 10:47

6 votes

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Why doesn't $\arccos x = -\tfrac12\sqrt{3}$ have any solutions?

answered Oct 25, 2014 at 11:46

6 votes

How to prove a sequence does not converge?

answered Oct 19, 2014 at 16:13

6 votes

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Every plane intersects set between $1$ and $5$ points

answered Nov 11, 2014 at 21:32

6 votes

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Let $f:\mathbb C\to\mathbb C$ is entire function. And $f(z+1)=f(z)$ and $f(z+i)=f(z)$ then what can you say about $f$?

answered Oct 9, 2014 at 11:25

5 votes

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Is it true that $P(A \mid B) + P(A^c\mid B) = 1$?

answered Oct 12, 2014 at 19:34

5 votes

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Understanding the integrating factor

answered Sep 1, 2014 at 19:14

5 votes

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Closed formula for the sum of the following series

answered Sep 16, 2014 at 21:20

5 votes

Prove $\lim_{n\to\infty}\frac{2n}{n+2}=2$

answered Sep 23, 2014 at 17:21

5 votes

$A^2 = 0$ and a square matrix A

answered Jul 2, 2014 at 17:36

5 votes

How do i find $(1+i)^{100}?$

answered Jun 26, 2014 at 19:58

5 votes

Geometric interpretation of complex eigenvalues

answered Jul 30, 2014 at 18:20

5 votes

Using the definition of a derivative

answered Jul 7, 2014 at 19:10

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391 Answers

Does it follow that $(n!)^n$ divide $(n^2)!$

Are set differences in a sigma algebra?

Sum of the squares of numbers

Example of algebra that is not a $\sigma$-algebra

How do I solve $y' = \sin(x - y)$?

Fibonacci Numbers Proof: $ f_n = \binom n0 + \binom{n-1}1 +\dots+ \binom{n-k}k$

Converting recursive equations into matrices

Asymptotic behaviour of the integral of the quadratic mean of the coordinates on the hypercube

If in an inner product space $\langle x,u\rangle=\langle x,v\rangle$ for all $x$, show that $u=v$.

Prove that there are infinitely many integer solutions to a diophantine equation

How can the equation $e^{-x^{2}}-2x^2e^{-x^{2}}=0$ be solved

Using l'Hôpital rule to find $\lim_{x\to-\infty} xe^x$

Is the preimage of a bounded set also bounded?

Solve logarithmic equation for $x$ to find the inverse of $f(x)= \ln(x+\sqrt{x^2+1})$

$p,q,r$ primes, $\sqrt{p}+\sqrt{q}+\sqrt{r}$ is irrational.

Integrate a power of logarithm

How can I calculate the total number of possible anagrams for a set of letters?

Closure of $[1, 2] \cup [4, 5]$

Why doesn't $\arccos x = -\tfrac12\sqrt{3}$ have any solutions?

How to prove a sequence does not converge?

Every plane intersects set between $1$ and $5$ points

Let $f:\mathbb C\to\mathbb C$ is entire function. And $f(z+1)=f(z)$ and $f(z+i)=f(z)$ then what can you say about $f$?

Is it true that $P(A \mid B) + P(A^c\mid B) = 1$?

Understanding the integrating factor

Closed formula for the sum of the following series

Prove $\lim_{n\to\infty}\frac{2n}{n+2}=2$

$A^2 = 0$ and a square matrix A

How do i find $(1+i)^{100}?$

Geometric interpretation of complex eigenvalues

Using the definition of a derivative