![](http://thumb.1010pic.com/pic3/upload/images/201408/53/c48c6dc6.png)
ijÆóÒµÄ⽨ÔìÈçͼËùʾµÄÈÝÆ÷£¨²»¼Æºñ¶È£¬³¤¶Èµ¥Î»£ºÃ×£©£¬ÆäÖÐÈÝÆ÷µÄÖмäΪԲÖùÐΣ¬×óÓÒÁ½¶Ë¾ùΪ°ëÇòÐΣ¬°´ÕÕÉè¼ÆÒªÇóÈÝÆ÷µÄÌå»ýΪ
Á¢·½Ã×£®¼ÙÉè¸ÃÈÝÆ÷µÄ½¨Ôì·ÑÓýöÓëÆä±íÃæ»ýÓйأ®ÒÑÖªÔ²ÖùÐβ¿·Öÿƽ·½Ã×½¨Ôì·ÑÓÃΪ3ǧԪ£¬°ëÇòÐβ¿·Öÿƽ·½Ã×½¨Ôì·ÑÓÃΪ4ǧԪ£®Éè¸ÃÈÝÆ÷µÄ×ܽ¨Ôì·ÑÓÃΪyǧԪ£®
£¨¢ñ£©½«y±íʾ³ÉrµÄº¯Êýf£¨r£©£¬²¢Çó¸Ãº¯ÊýµÄ¶¨ÒåÓò£»
£¨¢ò£©ÌÖÂÛº¯Êýf£¨r£©µÄµ¥µ÷ÐÔ£¬²¢È·¶¨rºÍlΪºÎֵʱ£¬¸ÃÈÝÆ÷µÄ½¨Ôì·ÑÓÃ×îС£¬²¢Çó³ö×îС½¨Ôì·ÑÓã®
£¨²Î¿¼¹«Ê½£ºÇòµÄ±íÃæ»ý¹«Ê½S=4¦Ðr
2£¬ÇòµÄÌå»ý¹«Ê½V=
¦Ðr
3£¬Ô²ÖùÌåµÄ²àÃæ»ý¹«Ê½S=2¦Ðrl£¬Ô²ÖùÌåµÄÌå»ý¹«Ê½V=¦Ðr
2l£©