Lazy Lee's user avatar
Lazy Lee's user avatar
Lazy Lee's user avatar
Lazy Lee
  • Member for 7 years
  • Last seen more than 1 year ago
  • California, United States
11 votes
Accepted

proof that $n^4+22n^3+71n^2+218n+384$ is divisible by $24$

8 votes
Accepted

Any integer in 99, 999, 9999... sequence is not a perfect square

8 votes
Accepted

Prove that a real polynomial $x^n+ a_1x^{n-1}+ \cdots +a_n$ cannot be completely resolved into linear factors if $a_1^2<a_2$.

8 votes
Accepted

To prove $\sum_{cyc}\frac{1}{a^3+b^3+abc} \le \frac{1}{abc}$

7 votes

Simplifying expression $\sqrt{6+2\sqrt{5}} - \sqrt{6-2\sqrt{5}}.$

6 votes
Accepted

Recurrence relation with variable $x$ in the denominator.

6 votes
Accepted

Prove $\frac{1}{r} = \frac{1}{a} + \frac{1}{b}$ for a semicircle tangent within a right triangle

6 votes
Accepted

Find all positive integer triplets $(x,y,z)$ in $x!+y!=15\cdot 2^{z!}$

5 votes
Accepted

problem in understanding The Z channel

5 votes
Accepted

if $S_{n+1}=\frac{4+3S_{n}}{3+2S_{n}}$ find $\lim_{n \to \infty} S_{n}$

4 votes

Compute $\lim\limits _{n\to \infty }\frac{1}{\ln (\ln n)}\sum\limits_{k=2}^{n} \frac{1}{k\ln k}$ without Taylor series

4 votes
Accepted

combinatorics license plate question

4 votes
Accepted

u substitution understaing

4 votes
Accepted

Probability number is divisible by 11

4 votes

Finding a sum of $1+\frac{1}{4\cdot2^{4}}+\frac{1}{7\cdot2^{7}}+\frac{1}{10\cdot2^{10}}+\cdots$

4 votes

Given $x,y,z >0$ and $xy^2z^3 = 108 $, what is the minimum value of $x+y+z$?

4 votes

Find the size of the central angle of a sector with the largest area

4 votes

Find the value of $k$ so that one root of the equations $3x^2+7x+(6-k)=0$ is $0$.

3 votes
Accepted

Polynomial puzzle

3 votes

Rewriting $1-x+x^2-x^3+\cdots+x^{16}-x^{17}$ using sum of geometric series

3 votes

Simple proof by induction for $a+ar+ar^2+...+ar^n$

3 votes
Accepted

Proving that $Pr(X\ge m/2) \ge 1/(m+1)$

3 votes
Accepted

Point $E$ on base $AD$ of trapezoid $ABCD$ is such that $AE = BC$. Segments $CA$ and $CE$ intersects diagonal $BD$ at $O$ and $P$ respectively.

3 votes
Accepted

How to get the measure?

3 votes

Proving a Line to bisect a line in a Triangle

3 votes
Accepted

How can i solve this question with Geometric distribution or random variables?

3 votes
Accepted

Geometry problem with bisectors

3 votes
Accepted

Radii of inscribed and circumscribed circles in right-angled triangle

3 votes
Accepted

estimate of sum by integral

3 votes
Accepted

Value of b for which Tr(ABC)<-18

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