279 reputation
19
bio website derek1906.site50.net
location United States, Hong Kong
age 19
visits member for 2 years, 1 month
seen Jul 6 at 20:53

QWERTYUIOP

 ASDFGHJKL

  ZXCVBNM

jQuery is taking over the world! http://i.stack.imgur.com/sGhaO.gif

function aboutMe(){
    var person = {
        name : "Derek",
        language : ["JavaScript", "Java", "PHP-some"],
        website : "http://derek1906.site50.net",
        use : function(){
            stayInStackOverflow(today);
        }
    }
    return person;
};

Hi there! I am the 283863 th user in stackoverflow.

Visit my website at:

(Actually both of them are the same.)


Jul
2
awarded  Curious
Jun
7
comment Evaluate $\displaystyle\sum_{k=1}^nk\cdot k!$
@B.S. - In Chinese it's called "Splitting Summation" (rough translation)
Jun
7
comment How to derive this formula? $\displaystyle n^2=\sum_{k=1}^n(2k-1).$
$x^2 \text{(a perfect square)} + (2x+1) \text{(an odd number)} = (x+1)^2 \text{(next perfect square)}$
Apr
4
revised Series is convergent but it seems it is divergent?
Typo
Apr
4
accepted Series is convergent but it seems it is divergent?
Apr
4
comment Series is convergent but it seems it is divergent?
I was wondering why the answer was $1$... and then I saw the edit.
Apr
4
comment Series is convergent but it seems it is divergent?
@labbhattacharjee - Oh wow thank you so much! I totally forgot telescoping series existed!
Apr
4
asked Series is convergent but it seems it is divergent?
Mar
14
accepted Prove that all values satisfy this expression
Mar
14
comment Prove that all values satisfy this expression
Oh I see, thanks.
Mar
14
comment Prove that all values satisfy this expression
But what about when $p\le0$?
Mar
14
asked Prove that all values satisfy this expression
Feb
13
revised How to find this limit $\lim_{x\to+\infty}f(x)=0$
Minor grammar fix
Feb
13
suggested suggested edit on How to find this limit $\lim_{x\to+\infty}f(x)=0$
Feb
13
accepted Computing the limit of this function
Feb
13
comment Computing the limit of this function
Thanks for the response!
Feb
13
comment Computing the limit of this function
Thanks for the response! Didn't realize I can combine them into one. Thank you so much.
Feb
13
revised Computing the limit of this function
added 5 characters in body
Feb
13
asked Computing the limit of this function
Feb
6
comment $xy=1 \implies $minimum $x+y=$?
Hey my TA showed us this in class before!