有没有哪位数学高手帮忙回答这个问题：三棱锥与三角锥可不可以等同啊？谢喽:-D
\u54ea\u4f4d\u9ad8\u624b\u5e2e\u5fd9\u89e3\u4e00\u4e0b\u5982\u4e0b\u51e0\u4e2a\u6570\u5b66\u9898\uff0c\u611f\u8c22\uff013\u3001\u9009D
5\u3001\u9009D
6\u3001\u9009B
7\u3001\u9009C
15\u3001\u9009C
18\u3001\u9009B
\u4ea7\u751f\u5dee\u5f02\u7684\u539f\u56e0\u662f\uff1a
1\u3001\u76f4\u89d2\u4e09\u89d2\u5f62ABD\u4e2d\uff0c\u663e\u7136\u89d2ABC\u4e0d\u662f30\u00b0
2\u3001\u5728\u76f4\u89d2\u4e09\u89d2\u5f62ABC\u4e2d\uff0cAB=4\u3001BC=8\uff0c\u5219\uff1a\u89d2ABC\u662f60\u00b0
\u662f\u9898\u76ee\u6709\u95ee\u9898\uff0c\u800c\u4e0d\u662f\u4f60\u7684\u89e3\u6cd5\u6709\u95ee\u9898\u3002
不可以，三角锥不一定是三棱锥也可以是四棱锥
应该是一样的
绛旓細鍙互绛夊悓锛屽彧鏄娉曚笉鍚岃屽凡锛屼綋绉兘鏄1/3x(搴曢潰绉痻楂橈級銆
绛旓細1锛庯紙鑷繁鍋氬浘锛屽浘娌＄矘杩囨潵锛夛紝鍙煡OC=10锛孊C=10 OA=18 鍓5绉掗挓锛孮鍦∣C娈碉紝鍚5绉掗挓鍦–B娈碉紝锛孭璧板畬OA闇瑕18绉掞紝Q鍏堝埌杈剧粓鐐 姝ゆ椂Q鍧愭爣鍙氳繃涓夎褰㈢浉浼兼潵纭畾 鍗冲綋X鈮5鏃 2X锛10=妯潗鏍囷細8=绾靛潗鏍囷細6 瑙ｅ緱Q锛8X/5锛6X/5锛夊綋5锛淴鈮10鏃 Q绾靛潗鏍囧缁堜负6锛屾鏃舵í鍧愭爣=8+2锛圶-5...
绛旓細鎵浠(x)<=f(0)=a*1+2=2+a a<0鐨勬儏鍐垫瘮杈冨鏉
绛旓細鍐欑殑寰堣缁嗕簡锛岃窡鐫绠椾竴閬嶅氨鎳備簡锛屼笉鎳傚啀闂
绛旓細9銆佹牴鍙5 10銆佸嬀鑲″畾鐞3:4:5锛屽緱鍒癮=6锛宐=8
绛旓細璁惧崟浠蜂负8鍏冪殑涔︿拱浜哫鏈紝鍒欏崟浠蜂负12鍏冪殑涔︿拱浜嗭紙105-X锛夋湰,绗旇鏈殑鍗曚环涓篩鍏 8X+12(105-X)+Y=1500-418 1260-4X+Y=1082 4X-Y=178 鍥犱负Y灏忎簬10鎵浠4XI澶т簬178鑰屼笖灏忎簬188 X澶т簬44.5灏忎簬47 X =45鎴栬46 褰揦=45鏃禮=2 褰揦=46鏃禮=6 甯屾湜瀵逛綘鏈甯姪(*^__^*)...
绛旓細鍏ㄩ儴绛変簬浜屽崄鍥涳紝鐩稿姞鍒氬ソ绛変簬浜屽崄鍥
绛旓細0<(x/2)ln[(x+1)/(x-1)]-1,<==>1<ln{[1+2/(x-1)]^(x/2)},<==>e<[1+2/(x-1)]^(x/2),鈶狅紝璁総=(x-1)/2>0,鍒檟=2t+1,鈶犲彉涓(1+1/t)^(t+1/2)>e,璁緁(t)=(1+1/t)^(t+1/2),t>0,f'(t)=(1+1/t)^(t+1/2)*[ln(1+1/t)+(t+1/2)/...
绛旓細璇佹槑锛 (鏂规硶涓)tan^2a=2tan^2b+1 sin^2a/(1-sin^2a)=2sin^2b/(1-sin^2b)+1 sin^2a/(1-sin^2a+sin^2a)=(sin^2b+1)/(1-sin^2b+sin^2b+1)sin^2a=(sin^2b+1)/2 鎵浠ワ細sin^2b=2sin^2a-1 (鏂规硶浜) 濡傚浘
绛旓細姣忓ご鐗涙瘡澶╁悆x锛屾瘡浜╂瘡澶╃敓闀块熷害涓簓锛10*30*x = 5 + 30*5*y => 60*x = 1 + 30*y 28*45*x = 15 + 45*15*y => 84*x = 1 + 45*y x = 1/12, y = 2/15 绗3鍧楀湴z澶寸墰鍚80澶 z*80*x = 24 + 80*24*y => z = 42 鍙傝冭祫鏂欙細http://zhidao.baid...
