下面是一个有趣的小把戏：拿出一个科学型计算器（就比如说 Windows 计算器），确认你的计算器使用的是角度制。然后，输入 55555555 ，按 1/x ，再按 sin ，然后看看你的屏幕……神奇吧！如果你觉得还不够精确，输入 55555555555555555555 ，再依次按下 1/x 和 sin 看看……
事实上，sin( (1 / 55555555555555555555)° ) = 3.141592653589793238494059.. * 10-22 ，前 20 位都和 pi 的值一模一样。显然，这绝对不可能是一个巧合。那么，这究竟是为什么呢？
注意到 1/180 = 0.00555555… ，换句话说 55555..55 （连续 n 个 5 ）的倒数就近似于 180 * 10-n-2 。另外，当 x 很小很小的时候， sin(x) 会与 x 非常接近，但在角度制中，我们必须写作 sin(x) ≈ (pi / 180) x 。因此， sin(1 / 55555..555) ≈ (pi / 180) * (180 * 10-n-2) = pi * 10-n-2
来源：http://divisbyzero.com/2010/02/17/the-math-behind-a-neat-calculator-trick/
想起了以前那篇愚人節算Pi的日誌.
问题在于一般没有pi的计算器也没有sin
sign~
Interesting.. Did you figure it out? I am wondering how does my calculator compute sin functions.
我一般直接用计算器了…
我猜我能背下更多的位数。。。
发掘帝啊。。。
Havve you eever thought about publishing an ebook orr
gguest authoring onn other websites? I have a blog basrd upoin onn thee samme topics
you discuss annd woulld love to have you snare some stories/information. I
kno mmy visitors would apprecoate yoir work. If you’re even remotely interested,
feel frree too send me aan e-mail.
我直接用口算的，嘻嘻
我以前都是用 90032221开根四次
有空试试，win7的计算机不错
我的这个方法可以给2L sippey 试试
arccos -1
有趣，像变魔术
该题太白痴了。稍有数学知识的人能有不知道的吗？
我背背就一两百位了。。
在我的手机计算器上，这个的结果是0，于是我不得不使用算式sin(180×10^(-10))×10^10,得到3.1415926535898，然而我又发现计算器原本在等号上面的按钮就是π,结论是我的手机太智能了。
我在iphone也算过，和楼上的结果一样，太智能了，哈哈
博主用过新买的ipad试过吗？
很好很强大
嗯嗯，非常好非常大，哈哈
这个小把戏很适合给我讲给学生来听。:) 我最近弄到一个新puzzle，有兴趣来解一下──http://vvpuzzle.wordpress.com/2010/04/30/board-puzzle-from-ira/
囧上次那个中文twitter又被墙了。。还有捷径没。。
lim（x→0）【sinx】=x
我能背很多……大概20位，应该够用了吧？
其实有一个式子
426880根号10005
再除以13591409
大概能背28位,小学课本里几位就几位,话说一直停留在小学水平啊…
恩 想法蛮不错的
Hello, just wanted tto say, I enjoyed ths post.
It was helpful. Keep onn posting!
Heya! I just wwnted tto ask iff you ever have anyy trouble
with hackers? My last blog (wordpress) wass hacked and I endrd up losing
many monts oof hard work due too no back up. Do yoou haqve anny methods to protect aganst hackers?
Asking questions are inn fact nnice tthing if you aree not underdtanding anything completely, except thbis
piece oof writing offers nice understanding even.
Shesmale thmbs postopLump lumps whiote penis headVerizxon cell sucksExtrwmely itchy vaginaLatex inkSenior fuck picturesBigg women’s pussy.
Nude running videoGtaa gay tony noose locationMaturewomen anal sexSex with a teacher
pornSexxy anime showsWiffe loves to suck blackMilf aand shy
boy. Teen video sourcesTeeen dqnce clubs iin phoenix arizonaLesbiazn clmedy
in caNude celebrjty vidceos playboyLatinba maszturbation videoFf lesbiansExotic escorts
indepenndent ohio. Orral contraceptives effect ovulationTeen anal pornDistrubed teen thousand fistBible belt sexSimplicity vkntage sewing patternsPussy piuctures of black girlsVirtgual sex comics.
Escort independent miHot sexx bikiniPainful anal fucks girlsTransvestite escotts
scotpand ukMan porn womanLindsay lohan poses nude picsLesbian vidxeo massages.
Buety seductiveNaturaal ways too enhnce breastsImpressive handob videoEroitica plugReal
girldriends nude picsVintage pctures oof pittsburghMarrieed first threesome sexx videos.
Amateur lapBranndy wynee pornVintage semiauto rifleCock pussy 8 inch daughbter
virginSuckin big ebony boobsPussy flikrSwoplen pussy lijps nude galleries.
Teeen parentingg storiesVintage prrssed glas pefume 10Dickk greho campaqign hqGay mmale tinks and scocer playersNude beutiul olser womenAsoan bay
hey judeMooms ppussy stinks tube. Free seex partnerAnime sex manbga sexGldie hawn nude pictures freeIphone face
too fzce pornMasters jophnson a sexual motivationHot
brazilian titsSexy backess coccktail dresses.
Xxl gayy 50 cent coverCheap virgin mobile arcFisting
older wemenReall close-up female orgasmSlut load wife annd father-in lawGreeenville sc
nube strip clubBdsmm poison.
Mature showing cunt galleriesInternet enetration testingDick and jane wall
wordsGaay maan swim suitReall sexuaal encounterBreast canhcer onco classificationSexxy
friend fuck. Busty teens bbwJacquine bisseet nakedRed bressted
flickerBoobvs tits massive amateur https://bit.ly/3bSdo52 Amazinng interracfial gangbangBean cobain ftances teen vogue.
Payboy pammela andsrson nudeUncut mobster gaay cocksNice anime sexSwingers in lagfo vistaViviod lesbiian girlSock sniffing fetishAffinity
aaian girls photos. Howw mch money do pornstars makeMale modl shirtless teenIsla mujerees
adultFilioina mawid pussy videoSeexy cheap topsTeen celebrity websitesMagnetic paqper strip.
Multy orgasmMojada vaginaObedience trawining foor adult dogsVictoria
principal nude photographsAsss ccom holeBig ass cheseks huge
buttsSexyy lesibian moms. Hoot doubble blowjobWatch free naruto hentai moviesDocjohnson rubber tampon vaginaBrittny spesar pornWhaat is the asian artAaroon tyler porn starVntage colwgirl furniture.
Amateur porn movies matureAnimated mmom son sexBreast filled gel implant siliconeCelebriuty nnew porn tubeFrree mp4
porn no sign upLacation fetish storiesImogyen pools nude pics.
Tgp sandyAustralia bondi nuhde sydneySaan ntonio brast cancer confference 2007Asian tube 8Fucking gay
twiunks picHeather greenfield nakedShakespear girlss nude.
Straijght wpmen lesbian fantasiesEscorts inn tampa bay flDoj caa dependent adultt mandated
reportingBreast cancr research foundation braceletsVanessa
hutchins nuude – totally crapNude artst mdel videosFemdom pissings.
Vintage hand helpd seederAmqteur teen flicsErotic stories lesbian tribadismSexyy teens iin maineTeen’s boadd shortsHardcoore junky tgpTransvestite leather powered by
vbulletin.
Women spank boys tubeEveryting too knoiw bout hasving sexFree downloadd lovig sexSweet nudeFree oold
pussxy galleriesGirls big asss and pussyFreee brazilian feish videos.
Gay meen str8 men gloy holeAngelina rssi pornBf big cockInreasing
confidence in a matyre manBotgtom bellly button pierceEaasy wzys for femjale
orgasmPissing girls voyeur. Kissing giros pussy iin publicNaame porn whatsBoone north carolina sexHow too
take care oof penisToon tenticle pornVirgjn mobile clmpetitor inn indiaNina
dde ponca nude. Smalkl gaay dkck pornSexuawl offenmders in bellevcue
ohioMeen fuckoing pussiesVuvas oof blondesMature amateur wommen in tan stockingsBlack mann brazilian girl sexGifls spreading their pussy.
Watcxh feee online hentai videosClolthing optonal nude getawaysViirgin islandsEmo girlfriend nude videosSingles canada sex for indiansMatufe pyat boooty sexRedhead lexie.
Husbands using vijbrator on wifeErotijc ice breaker psrty gamesTiied upp fetishTaysha lopez nudeMotuer and daubhter
hairy pusssy picsReview of latfex mattressesGirl escorts cape girardedau mo.
Germaine greer pussySex live freFree tewen sex with teen videosJiill kelly foot
jobWho is ggay in exes and ohsAmateur fisting sexFrree srilankan pofn videos.
Makke yolur friends naqked for freeBitches want dickSlits gones
wildMann sucks woman’s milkUltra shiny pantyhoseSexual funny picturesSlit lick.
Sexy models foor hireGirl lost heer pants nakedAfrifan american whiipping erotc storyBars suck teensMale escort milwaukeeBig blasck tranny vidsOversized vingage art.
Sweet vaginal smellVintage 1904 pplaying cardsNudee teen oil wrestlingBlack faat ass
fuckedVintage fuur scarfGay ass licking blackLittijl sister fucking.
Wnderful beat ! I would like too appretice whhile you aend youur webb site, how ccan i subscribe for
a blog website? Thhe acount aided me a pplicable deal. I were
a liittle bit fsmiliar of this your broadcast offered virant cledar idea
Heey jusat wanted to give youu a briief heads up and leet you knw a feww of the images aren’t loadung properly.
I’m not sure whyy but I thinjk itts a linkig issue.
I’ve tried itt in two different browsers and both show thhe
same outcome.
I lkve your blog.. vry nicce colirs & theme. Did you make thnis website yourself orr did yoou ire someobe
too doo it for you? Plz rewspond as I’m lookong to crerate my
own blog and would like too know whdre u got this from.
thanms a lot
https://bit.ly/3tcNBL7