ÌâÄ¿ÄÚÈÝ
11£®Îª¼õÉÙ¿ÕÆøÎÛȾ£¬Ä³ÊйÄÀø¾ÓÃñÓõ磨¼õÉÙȼÆø»òȼú£©£¬²ÉÓ÷ֶμƷѼÆËãµç·Ñ£¬Ã¿ÔÂÓõ粻³¬¹ý100¶Èʱ£¬°´Ã¿¶È0.57Ôª¼ÆË㣬ÿÔÂÓõçÁ¿³¬¹ý100¶Èʱ£¬ÆäÖеÄ100¶ÈÈÔ°´Ô±ê×¼ÊÕ·Ñ£¬³¬¹ýµÄ²¿·Ö°´Ã¿¶È0.5Ôª¼ÆË㣮£¨1£©ÉèÔÂÓõçÁ¿xʱ£¬Ó¦½»µç·ÑyÔª£¬Ð´³öyÓëxµÄº¯Êý¹Øϵʽ£»
£¨2£©Ð¡Ã÷µÚÒ»¼¾¶ÈµÄµç·ÑÇé¿öÈçÏ£º
ÔÂ·Ý | Ò»Ô | ¶þÔ | ÈýÔ | ËÄÔ |
½»·Ñ½ð¶î | 76Ôª | 63Ôª | 45.6Ôª | 184.6Ôª |
·ÖÎö £¨1£©¸ù¾ÝÓ¦½»µç·Ñ=ÔÂÓõç¶ÈÊý¡Áÿ¶Èµç·Ñ½¨Á¢º¯Êý¹Øϵ£¬ÒòΪÿ¶Èµç·Ñ±ê×¼²»Ò»Ñù£¬ÐèÒª·ÖÀàÌÖÂÛ£»
£¨2£©·Ö±ð¸ù¾ÝÿÔÂËù½»µç·Ñ£¬Çó³öÿÔÂËùÓõçµÄ¶ÈÊý£¬×îºóÏཻ¼´¿ÉÇó³öËùÇó£®
½â´ð ½â£º£¨1£©µ±0¡Üx¡Ü100ʱ£¬y=0.57x£»
µ±x£¾100ʱ£¬y=0.5¡Á£¨x-100£©+0.57¡Á100=0.5x-50+57=0.5x+7£®
ËùÒÔËùÇóº¯ÊýʽΪy=$\left\{\begin{array}{l}0.57x£¬0¡Üx¡Ü100\\ 0.5x+7£¬x£¾100\end{array}\right.$--£¨6·Ö£©
£¨2£©¾ÝÌâÒ⣬
Ò»Ô·ݣº0.5x+7=76£¬µÃx=138£¨¶È£©£¬
¶þÔ·ݣº0.5x+7=63£¬µÃx=112£¨¶È£©£¬
ÈýÔ·ݣº0.57x=45.6£¬µÃx=80£¨¶È£©£®
ËùÒÔµÚÒ»¼¾¶È¹²Óõ磺
138+112+80=330£¨¶È£©£®
¹ÊСÃ÷¼ÒµÚÒ»¼¾¶È¹²Óõç330¶È£®--£¨12·Ö£©
µãÆÀ ±¾ÌâÖ÷Òª¿¼²éÁ˺¯ÊýÄ£Ð͵ÄÑ¡ÔñÓëÓ¦Óã¬ÒÔ¼°¸ù¾Ýº¯ÊýÖµÇó×Ô±äÁ¿£¬ÊôÓÚ»ù´¡Ìâ
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿
20£®ÒÑÖª±äÁ¿xºÍyÂú×ã¹Øϵy=0.1x-10£¬±äÁ¿zÓëy¸ºÏà¹Ø£¬ÔòÏÂÁнáÂÛÖÐÕýÈ·µÄÊÇ£¨¡¡¡¡£©
A£® | xÓëy¸ºÏà¹Ø£¬xÓëz¸ºÏà¹Ø | B£® | xÓëyÕýÏà¹Ø£¬xÓëzÕýÏà¹Ø | ||
C£® | xÓëyÕýÏà¹Ø£¬xÓëz¸ºÏà¹Ø | D£® | xÓëy¸ºÏà¹Ø£¬xÓëzÕýÏà¹Ø |
16£®¹ýµã$P£¨-\sqrt{3}£¬-1£©$µÄÖ±ÏßlÓëÔ²x2+y2=1ÓÐÁ½¸ö²»Í¬µÄ¹«¹²µã£¬ÔòÖ±ÏßlµÄбÂʵÄÈ¡Öµ·¶Î§ÊÇ£¨¡¡¡¡£©
A£® | $£¨0£¬\frac{{\sqrt{3}}}{3}£©$ | B£® | $[0£¬\sqrt{3}]$ | C£® | $[\frac{{\sqrt{3}}}{3}£¬\sqrt{3}£©$ | D£® | $£¨0£¬\sqrt{3}£©$ |
20£®Ä³¼¸ºÎÌåµÄÈýÊÓͼÈçͼËùʾ£¬ÔòËüµÄÌå»ýÊÇ£¨¡¡¡¡£©
A£® | $\frac{¦Ð}{12}$ | B£® | $1-\frac{¦Ð}{12}$ | C£® | $1-\frac{¦Ð}{3}$ | D£® | 1-$\frac{¦Ð}{6}$ |