#1
|
|||
|
|||
͹ءÃÁ
1+1/2+1/3+...+1/1020=??
25 Á¡ÃÒ¤Á 2012 21:30 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 1 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ T.T N |
#2
|
||||
|
||||
äÁè¹èÒÁդӵͺÊÇÂæ¤ÃѺ ¾Ç¡ Harmonic Series ËÃ×ͨÐàÍҤӵͺ¨Ò¡ Wolfram ¡çä´é´Ñ§¹Õé
à¾Ô觹֡ä´éÇèÒÁÕÇÔ¸Õ»ÃÐÁÒ³ÍÂÙè¤×Í ãªé Euler-Mascheroni Constant ¤ÃѺ ¹ÔÂÒÁ $$\gamma=\lim_{n\rightarrow \infty}1+\frac{1}{2}+\frac{1}{3}+\cdots+\frac{1}{n}-\ln n$$ ´Ñ§¹Ñé¹ ¤èÒ»ÃÐÁÒ³¨Ö§à»ç¹ $\ln 1020 + \gamma = 7.50477$ «Ö觤èÒ¨ÃÔ§¤×Í $7.50526$
__________________
keep your way.
27 Á¡ÃÒ¤Á 2012 23:51 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 1 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ PP_nine |
#3
|
|||
|
|||
¼Á¡ÓÅѧËÒÊٵáÒäӹdz͹ءÃÁ¹Õé¾Í´Õ à¾ÃÒÐÅÙ¡ÊÒÇ¡ÓÅѧàÃÕ¹àÃ×èͧ¹ÕéÍÂÙè áÅÐä»à¨ÍÊٵèҡ¢éÒ§ÅèÒ§¹Õé¾Í´Õ
http://math.stackexchange.com/questi...cdots-frac-1-n 1+1/2+1/3+...+1/1020=?? Sn=1+1/2+1/3+...+1/n=LN(n+.5)+0.5772+1/(24*n^2) n=14, Sn=3.251562 ¤èÒ»ÃÐÁÒ³ä´é = 3.251561 n=16, Sn=3.495108 ¤èÒ»ÃÐÁÒ³ä´é = 3.495183 n=1020 ¤èÒ»ÃÐÁÒ³ Sn=LN(1020+.5)+0.5772+1/(24*1020^2)=7.505461 ãªéÊٵùÕé¤èÒ n ÊÙ§æ¤èÒ·Õè¤Ó¹Ç³ä´é¨ÐÊÙ§ÇèÒ¤èÒ¨ÃÔ§àÅ硹éÍ áµèà»ÃÕºà·ÕºáÅéÇáÁè¹ÂÓ¡ÇèÒÊٵ÷Õè¤Ø³ PP_nine áÊ´§µÑÇàÅ¢ÁÒ
__________________
ãªéàÇÅÒÇèÒ§ÈÖ¡ÉÒ¤³Ôµà¾×è͵ÔÇÅÙ¡ ¹Ñ¡àÃÕ¹ÈÖ¡ÉÒ¹ÒÃÕ áÅзÇÕ¸ÒÀÔàÈ¡ http://www.facebook.com/bpataralertsiri ¤³ÔµÁѸÂÁ»ÅÒ http://www.facebook.com/groups/HighSchoolMath/ 11 ¡Ã¡®Ò¤Á 2012 09:05 : ¢éͤÇÒÁ¹Õé¶Ù¡á¡éä¢áÅéÇ 1 ¤ÃÑé§, ¤ÃÑé§ÅèÒÊØ´â´Â¤Ø³ áÁèãËéºØÁÒ à˵ؼÅ: à¾ÔèÁàµÔÁ¢éͤÇÒÁ |
#4
|
||||
|
||||
ÍéÒ§ÍÔ§:
__________________
»Õ¹Õé µéͧäÁè¾ÅÒ´ ÊÙéà¾×èÍ ÁÈÇ »·ØÁÇѹ |
|
|