某商场为促销要准备一些正三棱锥形状的装饰品,用半径为10cm的圆形包装纸包装，要求如下：正三棱锥
\u67d0\u5546\u573a\u4e3a\u4fc3\u9500\u8981\u51c6\u5907\u4e00\u4e9b\u6b63\u4e09\u68f1\u9525\u5f62\u72b6\u7684\u88c5\u9970\u54c1\uff0c\u7528\u534a\u5f84\u4e3a10cm\u7684\u5706\u5f62\u5305\u88c5\u7eb8\u5305\u88c5\uff0e\u8981\u6c42\u5982\u4e0b\uff1a\u6b63\u4e09\u68f1\u9525\u7684\u5e95\u9762\u6b63\u4e09\u68f1\u9525\u5c55\u5f00\u5982\u56fe\u6240\u793a\uff0e\u5f53\u6309\u7167\u5e95\u8fb9\u5305\u88c5\u65f6\u4f53\u79ef\u6700\u5927\uff0e\u8bbe\u6b63\u4e09\u68f1\u9525\u4fa7\u9762\u7684\u9ad8\u4e3ah0\uff0c\u9ad8\u4e3ah\uff0e\u7531\u9898\u610f\u5f97\uff1a36x+h0=10\uff0c\u89e3\u5f97h0=10-36x\uff0e\u2026\uff082\u5206\uff09\u5219h=h02?x212=100?1033x\uff0cx\u2208\uff080\uff0c103\uff09\uff0e \u2026\uff085\u5206\uff09\u6240\u4ee5\uff0c\u6b63\u4e09\u68f1\u9525\u4f53\u79efV=13Sh=13\u00d7<div style="width: 6px; background-image: url(http://hiphotos.baidu.com/zhidao/pic/item/aa64034f78f0f736dcbbf8b50955b319ebc41338.jpg); background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; overflow-x: hidden; overflow-y: hidden; height: 11px; bac
\u5305\u88c5\u7eb8\u7684\u9762\u79ef\u662f\uff1a10*3.14*20\uff1d628\uff08\u5e73\u65b9\u5398\u7c73\uff09
\u5236\u4f5c\u4e00\u4e2a\u8fd9\u6837\u5c01\u95ed\u996e\u6599\u7f50\u9700\u8981\u7684\u94c1\u76ae\u9762\u79ef\u662f\uff1a628+\uff0810/2\uff09*\uff0810/2\uff09*3.14*2\uff1d785\uff08\u5e73\u65b9\u5398\u7c73\uff09
三棱锥的底面和圆形包装纸如图所示，根据题意AB=BC，有等边三角形的性质可计算OB=BC/3=AB/3，AB=10/4 X3=7.5，OB=10/4=2.5。三角形的边长=2X2 .5√3=5√3。正三棱锥的高=√（5√3）^2-5^2=5√2。
V=75(√3)/4
边长X=5√3
圆内接正三角形，折成正三棱锥。该三棱锥边长X=5√3
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绛旓細瑙ｆ瀽锛氭槗鐭锛3锛=10锛庣敱棰樻剰鐭锛2锛夋瘮f锛1锛夊鏈搴曞眰锛1+2锛堜釜锛夛紝f锛3锛夋瘮f锛2锛夊鏈搴曞眰锛1+2+3锛堜釜锛夛紝f锛4锛夋瘮f锛3锛夊鏈搴曞眰锛1+2+3+4锛堜釜锛夛紝鈥锛坣锛夋瘮f锛坣-1锛夊鏈搴曞眰锛1+2+3++n锛堜釜锛夛紝鈭磃锛坣锛-f锛坣-1锛=1+2+3+鈥+n=n(n+1)2锛庘埓鐢辩疮鍔犳硶鍙緱f...
绛旓細锛1锛 =10锛2锛 = 閫氳繃瑙傚療鍙煡f(3)=10.(2)鍦ㄦ眰f(n)鏃讹紝鍙互瑙傚療褰掔撼鍑篺(n)鐨勯掓帹鍏崇郴 ,鐒跺悗鍐嶉噰鐢ㄥ彔鍔犳眰閫氶」鐨勬柟娉曟眰鍑 .
绛旓細鎵浠 鐨勭郴鏁颁负 14銆佸湪寰峰浗涓嶈幈姊呬妇琛岀殑绗48灞婁笘涔掕禌鏈熼棿,鏌愬晢鍦姗辩獥閲岀敤鍚屾牱鐨勪箳涔撶悆鍫嗘垚鑻ュ共鍑嗏姝ｄ笁妫遍敟鈥濆舰鐨勫睍鍝,鍏朵腑绗竴鍫嗗彧鏈変竴灞,灏变竴涓箳涔撶悆;绗2銆3銆4銆佲﹀爢鏈搴曞眰(绗竴灞)鍒嗗埆鎸夊浘4鎵绀烘柟寮忓浐瀹氭憜鏀.浠庣涓灞傚紑濮,姣忓眰鐨勫皬鐞冭嚜鐒跺瀿鏀惧湪涓嬩竴灞備箣涓,绗琻鍫嗙n灞傚氨鏀句竴涓箳涔撶悆,浠 琛ㄧず绗琻...
绛旓細涓婅繖涓綉鐪嬬湅http://news.sina.com.cn/o/2006-06-10/06069166996s.shtml 鍙傝冭祫鏂欙細http://news.sina.com.cn/o/2006-06-10/06069166996s.shtml
绛旓細浠巒灞傜畻璧凤紝绗琻灞傛渶搴曞眰涓鸿竟闀夸负n涓悆鐨勬渶澶ф涓夎褰紝鏈搴曞眰鐨勭浜屽ぇ姝ｄ笁瑙掑舰涓簄-1涓悆锛屼緷娆＄被鎺ㄦ渶涓棿涓1涓悆 绗 n 灞傛荤悆涓 G(n)=3*(n-1)+3*[(n-1)-1]+3[(n-2)-1]鈥︹+1 =3*n*(n-1)/2 鍒欑 n 鍫嗕负 f(n)=G(1)+...+G(n)=1.5{[n^2+(n-1)...
