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Imago's user avatar
Imago's user avatar
Imago
  • Member for 9 years, 8 months
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7 votes

What does "closed under ..." mean?

7 votes
Accepted

Limit of $\frac{n^2}{n!}$

3 votes

prove that $ -2 + x + (2+x)e^{-x}>0 \quad \forall x>0$

3 votes

Find $\lim_{n\to \infty} \int_n^{n+1} {\sin x \over x} dx$

3 votes

Limit problem $e^x$ without L'Hôpital's rule

2 votes
Accepted

$\lim_{(x,y)\to(0,0)}\frac{x^2y^2}{\sin(x)\cos(y)}$ is this done correctly?

2 votes

all but finitely many terms

2 votes
Accepted

What is $x^{2/3}$ when $x$ is negative?

2 votes

If $\sum a_n$ converges and $(b_n)$ converges, then does $\sum a_nb_n$ converge?

1 vote

Explanation of proof by contradiction

1 vote

How to approach this sequence? (elementary number theory)

1 vote

If $|f|$ can be integrated using Riemann integration, does that mean that $f$ can be integrated using Riemann integration?

1 vote

Proving $4^n > n^4$ holds for $n\geq 5$ via induction.

1 vote

How prove $\bigl(\frac{\sin x}{ x}\bigr)^{2} + \frac{\tan x }{ x} >2$ for $0 < x < \frac{\pi}{2}$

1 vote

Prove that $(n!)^{\frac{1}{n}} < ((n+1)!)^{\frac{1}{n+1}}$

1 vote

What is the remainder when $6\times7^{32} + 7\times9^{45}$ is divided by $4$?

0 votes

Evaluate the summation $\sum_{k=1}^{n}{\frac{1}{2k-1}}$

0 votes

How to solve this integration: $\int_0^1 \frac{x^{2012}}{1+e^x}dx$

0 votes

Why is an automorphism of $\mathbb R$ continuous

0 votes
Accepted

Is it possible to split a division problem into parts, like in multiplication?

0 votes

Part of a proof that the product of an odd and even integers is even

0 votes

Intuition to why average of the square of a positive integer and the integer itself is the sum of all numbers from 1 to the integer?

0 votes

How to compute $\lim_{x\to\infty} \frac{9x}{\sqrt{x^2+1}}$

0 votes

Show convergence for $a_n = \frac{a_{n-1}}{2} + 1$ with $a_0 = 0$

0 votes

Expand $(3x^2+y)^5$

0 votes

How many possibilities with $x_1+x_2+x_3=20$ and some restrictions on the x's?

0 votes

Combinatorial proof of summation of $\sum_{k = 1}^{n-1} {n \choose k}= 2^1 + 2^2 + 2^3 +\ldots+ 2^{n-1}$

0 votes

Solve for $x$: $1024 = 2(3x+7)^{3/2}$

0 votes

Is $\int_{\sin x}^{\cos x}x\, dx$ not a well-defined integral?

0 votes

Which one grows asymptotically faster $g(n) = 10^{120} n \sqrt{n}$ or $f(n) = 3^{\log n}$?