|
ÊÁѤÃÊÁÒªÔ¡ | ¤ÙèÁ×Í¡ÒÃãªé | ÃÒª×èÍÊÁÒªÔ¡ | »¯Ô·Ô¹ | ¢éͤÇÒÁÇѹ¹Õé | ¤é¹ËÒ |
|
à¤Ã×èͧÁ×ͧ͢ËÑÇ¢éÍ | ¤é¹ËÒã¹ËÑÇ¢é͹Õé |
#1
|
||||
|
||||
͹ءÃÁ͹ѹµì ¤Ô´äÁèÍÍ¡
1.$\frac{1}{1*2} +\frac{1}{2*3} +\frac{1}{3*4}+...$
2.¨§ËÒ¤èҢͧ$\frac{1}{1}+\frac{1}{1+2}+\frac{1}{1+2+3} +....$ Thanks a lot !
__________________
|
#2
|
||||
|
||||
¤Óá¹Ð¹Ó
1. $\frac{1}{n(n+1)}=\frac{1}{n}-\frac{1}{n+1}$ 2. ¼ÅÃÇÁµÑÇÊèǹÍÂÙèã¹Ãٻ㴠ÊÒÁÒöãªé¢éÍ¡è͹˹éÒä´éËÃ×ÍäÁè
__________________
¤¹ä·ÂÃèÇÁã¨ÍÂèÒãªéÀÒÉÒÇÔºÑµÔ ½Ö¡¾ÔÁ¾ìÊÑÅѡɳìÊÑ¡¹Ô´ ªÕÇÔµ(¤¹µÍºáÅФ¹¶ÒÁ)¨Ð§èÒ¢Öé¹àÂÍÐ (¨ÃÔ§æ¹Ð) Stay Hungry. Stay Foolish. 13 Á¡ÃÒ¤Á 2010 11:17 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 1 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ nongtum à˵ؼÅ: á¡éà¤Ã×èͧËÁÒè |
#3
|
||||
|
||||
ÍéÒ§ÍÔ§:
1.$\frac{1}{1*2} +\frac{1}{2*3} +\frac{1}{3*4}+...$ $\frac{1}{2*3} = \frac{1}{6}$ ´Ù $\frac{1}{6} = \frac{1}{2}-\frac{1}{3}$ $\frac{1}{3*4} = \frac{1}{12}$ ´Ù $\frac{1}{12} = \frac{1}{3}-\frac{1}{4}$ µÍº $1$ ¶éÒäÁè¼Ô´¤ÃѺ ¼ÁÇèÒ ¹éͧ¢éÒÇ»Ñé¹ ¤§·Óä´é¡è͹ÁÒ¶ÒÁ áÅéÇ ^^
__________________
Fortune Lady
13 Á¡ÃÒ¤Á 2010 18:04 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 1 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ Siren-Of-Step |
#4
|
||||
|
||||
ÍéÒ§ÍÔ§:
ä˹æ¡ÃзÙé¹Õé¡çà»ç¹àÃ×èͧ¢Í§Í¹Ø¡ÃÁáÅéÇ ¼Á¢Í¶ÒÁ¹Ô´¹Ö§¹Ð¤ÃѺÇèÒ $\frac{1}{11}-\frac{1}{1100}+\frac{1}{111}-\frac{1}{111000}+\frac{1}{1111}-\frac{1}{11110000}+... = ? $ ¢ÍÇÔ¸Õ·Ó´éǹФÃѺ |
#5
|
||||
|
||||
·ÓÂѧ䧤ÃѺ ¹Õèè
__________________
Fortune Lady
|
#6
|
||||
|
||||
ÍéÒ§ÍÔ§:
$\frac{1}{11}-\frac{1}{1100}+\frac{1}{111}-\frac{1}{111000}+\frac{1}{1111}-\frac{1}{11110000}+... = ? $ $\frac{100}{1100}-\frac{1}{1100}+\frac{1000}{111000}-\frac{1}{111000}+\frac{10000}{11110000}-\frac{1}{11110000}+... = ? $ $\frac{99}{1100}+\frac{999}{111000}+\frac{9999}{11110000}+... = ? $ ........... 13 Á¡ÃÒ¤Á 2010 19:30 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 1 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ Scylla_Shadow |
#7
|
||||
|
||||
ÍéÒ§ÍÔ§:
¤ÓµÍº·Õè¹èÒ¨Ðà»ç¹ ¤×Í 0.999... ¨Ð¶Ù¡äËÁ¹éÒ |
#8
|
||||
|
||||
ãªè¤ÃѺ
àÍÒÍÂèÒ§§èÒ¡ÇèÒ¹Ñé¹Ë¹èÍ´աÇèÒ à»ç¹ 0.1 ä´é»èФÃѺ |
#9
|
||||
|
||||
ªèÇ·ӵèÍ·Õ¤ÃѺ ¼Á ÂѧäÁèÍÍ¡ T^T
__________________
Fortune Lady
|
#10
|
||||
|
||||
Åͧ¡ÃЪҡÍÐäÃÍÍ¡ÊÑ¡ÍÂèÒ§ã¹áµèÅÐÍѹ´Ù¤ÃѺ (¼Á¾Ù´§§ä»à»ÅèÒ)
¨Ò¡¹Ñ鹡çºÇ¡µÒÁÍѸÂÒÈѤÃѺ ä˹æ¡çä˹æáÅéǹФÃѺ ¢Íú¡Ç¹ÍÕ¡ÊÑ¡¢éÍ $$\frac{1}{6}+\frac{1}{36}+\frac{3}{216}+\frac{17}{1296}+\frac{83}{7776}+... = ?$$ ÊèǹàËÁ×͹¨Ðà»ç¹ $$\frac{1}{6}+\frac{1}{6^2}+\frac{3}{6^3}+\frac{17}{6^4}+\frac{83}{6^5}+... = ?$$ áµèàÈÉÊÔ¤ÃѺ 13 Á¡ÃÒ¤Á 2010 21:13 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 2 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ SolitudE |
#11
|
||||
|
||||
¢Íº¤Ø³·Ø¡æ¤¹ÁÒ¡¤ÃѺ µÍ¹¹Õé¼Áä´éáÅéÇ
__________________
Fortune Lady
|
#12
|
||||
|
||||
ÍéÒ§ÍÔ§:
__________________
Fortune Lady
|
#13
|
||||
|
||||
¼Á¢Ø´ÁÒ¨Ò¡ªÕµÃÇÁÁԵ÷Õè¼ÁÊÐÊÁäÇéàÁ×è͹ҹÁÒáÅéǹФÃѺ(áµèÂѧäÁèà¡Ô¹ 3 »Õ)
¨ÓäÁèä´éáÅéÇÇèÒÁÒ¨Ò¡ä˹ ¢Í´Ñ¹ à¹×èͧ¨Ò¡â´¹àºÕ´ - - ÃÍà·¾ à·¾¡çäÁèÁÒ (ä»ä˹¡Ñ¹ËÇèÒ) ú¡Ç¹´éǹФÃѺ ×note by mod: àÅè¹àǺºÍÃì´â»Ã´ã¨àÂç¹æ¤ÃѺ 13 Á¡ÃÒ¤Á 2010 23:57 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 1 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ nongtum à˵ؼÅ: double post+á¡éàÅ硹éÍÂâ»Ã´ãªé»ØèÁá¡éä¢ |
#14
|
||||
|
||||
Åͧ¤é¹´Ù ¾ºÇèÒ ÅӴѺ 1,3,17,83,... ÁÕÖà·ÍÁ·ÑèÇä» ¤×Í $a_n=\frac{1}{3}(2\cdot5^n+(-1)^n)$ ¤ÃѺ
«Ö觶éÒà»ç¹ÅӴѺ¹Õé ¡ç¨Ñ´ãËéÍÂÙèã¹ÃÙ»·ÕèÊÒÁÒöãªéÊٵüÅÃÇÁ͹ءÃÁàâҤ³Ôµä´é¤ÃѺ «Ö觼Á·´áÅéÇä´éẺ¹Õé$$\frac16+\frac{1}{3\cdot6^2}\left(2\sum_{i=0}^\infty(\frac56)^n+\sum_{i=0}^\infty(-\frac16)^n\right)$$¤§·´µèÍàͧä´é¹Ð¤ÃѺ
__________________
¤¹ä·ÂÃèÇÁã¨ÍÂèÒãªéÀÒÉÒÇÔºÑµÔ ½Ö¡¾ÔÁ¾ìÊÑÅѡɳìÊÑ¡¹Ô´ ªÕÇÔµ(¤¹µÍºáÅФ¹¶ÒÁ)¨Ð§èÒ¢Öé¹àÂÍÐ (¨ÃÔ§æ¹Ð) Stay Hungry. Stay Foolish. |
#15
|
||||
|
||||
¢ÍÍÀѤÃѺ à¹×èͧ¨Ò¡àÇÅÒà¡çºä»½Ñ¹ÁѹÃÙéÊÖ¡á»Å¡æ - -
¼Á¢Ø´ä»à¨Íà©Å ¤×Í $\frac{1}{4}$ ¤ÃѺ áµèÂѧäÁè·ÃÒºÇÔ¸Õ·ÓÍÂÙè´Õ ú¡Ç¹µèÍàµÔèÁãËé´éǹФÃѺ |
|
|