ÌâÄ¿ÄÚÈÝ
£¨2011•³çÃ÷ÏضþÄ££©Ä³¹«Ë¾Éú²úijÖÖÏû·À°²È«²úÆ·£¬Äê²úÁ¿x̨£¨0¡Üx¡Ü100£¬x¡ÊN£©Ê±£¬ÏúÊÛÊÕÈ뺯ÊýR£¨x£©=3000x-20x2£¨µ¥Î»£º°ÙÔª£©£¬Æä³É±¾º¯ÊýÂú×ãC£¨x£©=500x+b£¨µ¥Î»£º°ÙÔª£©£®ÒÑÖª¸Ã¹«Ë¾²»Éú²úÈκβúƷʱ£¬Æä³É±¾Îª4000£¨°ÙÔª£©£®
£¨1£©ÇóÀûÈóº¯ÊýP£¨x£©£»
£¨2£©Îʸù«Ë¾Éú²ú¶àÉŲ̀²úƷʱ£¬ÀûÈó×î´ó£¬×î´óÀûÈóÊǶàÉÙ£¿
£¨3£©ÔÚ¾¼ÃѧÖУ¬¶ÔÓÚº¯Êýf£¨x£©£¬ÎÒÃǰѺ¯Êýf£¨x+1£©-f£¨x£©³ÆΪº¯Êýf£¨x£©µÄ±ß¼Êº¯Êý£¬¼Ç×÷Mf£¨x£©£®¶ÔÓÚ£¨1£©ÇóµÃµÄÀûÈóº¯ÊýP£¨x£©£¬Çó±ß¼Êº¯ÊýMP£¨x£©£»²¢ÀûÓñ߼ʺ¯ÊýMP£¨x£©µÄÐÔÖʽâÊ͹«Ë¾Éú²úÀûÈóÇé¿ö£®£¨±¾ÌâËùÖ¸µÄº¯ÊýÐÔÖÊÖ÷Òª°üÀ¨£ºº¯ÊýµÄµ¥µ÷ÐÔ¡¢×îÖµ¡¢ÁãµãµÈ£©
£¨1£©ÇóÀûÈóº¯ÊýP£¨x£©£»
£¨2£©Îʸù«Ë¾Éú²ú¶àÉŲ̀²úƷʱ£¬ÀûÈó×î´ó£¬×î´óÀûÈóÊǶàÉÙ£¿
£¨3£©ÔÚ¾¼ÃѧÖУ¬¶ÔÓÚº¯Êýf£¨x£©£¬ÎÒÃǰѺ¯Êýf£¨x+1£©-f£¨x£©³ÆΪº¯Êýf£¨x£©µÄ±ß¼Êº¯Êý£¬¼Ç×÷Mf£¨x£©£®¶ÔÓÚ£¨1£©ÇóµÃµÄÀûÈóº¯ÊýP£¨x£©£¬Çó±ß¼Êº¯ÊýMP£¨x£©£»²¢ÀûÓñ߼ʺ¯ÊýMP£¨x£©µÄÐÔÖʽâÊ͹«Ë¾Éú²úÀûÈóÇé¿ö£®£¨±¾ÌâËùÖ¸µÄº¯ÊýÐÔÖÊÖ÷Òª°üÀ¨£ºº¯ÊýµÄµ¥µ÷ÐÔ¡¢×îÖµ¡¢ÁãµãµÈ£©
·ÖÎö£º£¨1£©ÓÉÌâÒ⣬x=0£¬b=4000£¬ËùÒÔC£¨x£©=500x+4000£¬P£¨x£©=R£¨x£©-C£¨x£©=3000x-20x2-500x-4000=-20x2+2500x-4000£¬0¡Üx¡Ü100£®
£¨2£©P£¨x£©=-20(x-
)2+74125£¬£¨0¡Üx¡Ü100£¬x¡ÊN£©£¬ÓÉ´ËÄÜÇó³ö×î´óÀûÈóºÍÈ¡µÃ×î´óÀûÈóʱµÄ²úÁ¿£®
£¨3£©MP£¨x£©=P£¨x+1£©-P£¨x£©=-40x+2480£¨0¡Üx¡Ü99£¬x¡ÊN£©£®±ß¼Êº¯ÊýΪ¼õº¯Êý£¬ËµÃ÷Ëæ×ŲúÁ¿µÄÔö¼Ó£¬Ã¿Éú²úһ̨µÄÀûÈóÓëÉú²úǰһ̨ÀûÈóÏà±ÈÔÚ¼õÉÙ£»ËµÃ÷Éú²úµÚһ̨µÄÀûÈó²î×î´ó£»Éú²ú62̨ʱ£¬ÀûÈó´ïµ½×î´ó£®
£¨2£©P£¨x£©=-20(x-
125 |
2 |
£¨3£©MP£¨x£©=P£¨x+1£©-P£¨x£©=-40x+2480£¨0¡Üx¡Ü99£¬x¡ÊN£©£®±ß¼Êº¯ÊýΪ¼õº¯Êý£¬ËµÃ÷Ëæ×ŲúÁ¿µÄÔö¼Ó£¬Ã¿Éú²úһ̨µÄÀûÈóÓëÉú²úǰһ̨ÀûÈóÏà±ÈÔÚ¼õÉÙ£»ËµÃ÷Éú²úµÚһ̨µÄÀûÈó²î×î´ó£»Éú²ú62̨ʱ£¬ÀûÈó´ïµ½×î´ó£®
½â´ð£º½â£º£¨1£©ÓÉÌâÒ⣬x=0£¬b=4000£¬
ËùÒÔC£¨x£©=500x+4000£¬
P£¨x£©=R£¨x£©-C£¨x£©=3000x-20x2-500x-4000
=-20x2+2500x-4000£¬0¡Üx¡Ü100£®
£¨2£©P£¨x£©=-20(x-
)2+74125£¬£¨0¡Üx¡Ü100£¬x¡ÊN£©
ËùÒÔx=62»òx=63£®
P£¨x£©max=P£¨62£©=P£¨63£©=74120£¨°ÙÔª£©£®
£¨3£©MP£¨x£©=P£¨x+1£©-P£¨x£©=-40x+2480£¨0¡Üx¡Ü99£¬x¡ÊN£©
±ß¼Êº¯ÊýΪ¼õº¯Êý£¬ËµÃ÷Ëæ×ŲúÁ¿µÄÔö¼Ó£¬Ã¿Éú²úһ̨µÄÀûÈóÓëÉú²úǰһ̨ÀûÈóÏà±ÈÔÚ¼õÉÙ£»
µ±x=0ʱ£¬±ß¼Êº¯ÊýÈ¡µÃ×î´óֵΪ2480£¬ËµÃ÷Éú²úµÚһ̨µÄÀûÈó²î×î´ó£»
µ±x=62ʱ£¬±ß¼Êº¯ÊýΪÁ㣬˵Ã÷Éú²ú62̨ʱ£¬ÀûÈó´ïµ½×î´ó£®
ËùÒÔC£¨x£©=500x+4000£¬
P£¨x£©=R£¨x£©-C£¨x£©=3000x-20x2-500x-4000
=-20x2+2500x-4000£¬0¡Üx¡Ü100£®
£¨2£©P£¨x£©=-20(x-
125 |
2 |
ËùÒÔx=62»òx=63£®
P£¨x£©max=P£¨62£©=P£¨63£©=74120£¨°ÙÔª£©£®
£¨3£©MP£¨x£©=P£¨x+1£©-P£¨x£©=-40x+2480£¨0¡Üx¡Ü99£¬x¡ÊN£©
±ß¼Êº¯ÊýΪ¼õº¯Êý£¬ËµÃ÷Ëæ×ŲúÁ¿µÄÔö¼Ó£¬Ã¿Éú²úһ̨µÄÀûÈóÓëÉú²úǰһ̨ÀûÈóÏà±ÈÔÚ¼õÉÙ£»
µ±x=0ʱ£¬±ß¼Êº¯ÊýÈ¡µÃ×î´óֵΪ2480£¬ËµÃ÷Éú²úµÚһ̨µÄÀûÈó²î×î´ó£»
µ±x=62ʱ£¬±ß¼Êº¯ÊýΪÁ㣬˵Ã÷Éú²ú62̨ʱ£¬ÀûÈó´ïµ½×î´ó£®
µãÆÀ£º±¾Ì⿼²éº¯ÊýÔÚÉú²úʵ¼ÊÖеÄ×ÛºÏÔËÓ㬽âÌâʱҪÈÏÕæÉóÌ⣬עÒâÍÚ¾òÌâÉèÖеÄÒþº¬Ìõ¼þ£¬ºÏÀíµØ½øÐеȼÛת»¯£®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿