·ÖÎö £¨1£©¸ù¾Ý×Ô±äÁ¿Ó뺯ÊýÖµµÄ¶ÔÓ¦¹Øϵ£¬¿ÉµÃAµã×ø±ê£¬¸ù¾ÝÁ½µã¼äµÄ¾àÀ룬¿ÉµÃCµã×ø±ê£¬¸ù¾Ý´ý¶¨ÏµÊý·¨£¬¿ÉµÃ´ð°¸£»
£¨2£©Èçͼ2ÖУ¬×÷D¹ØÓÚÖ±ÏßACµÄ¶Ô³ÆµãD¡ä£¬Á¬½ÓDD¡ä½»ACÓÚH£¬Á¬½ÓDEÓÉ´ËDE½»CCÓÚP£¬´Ëʱ|PD-EP|µÄÖµ×î´ó£®
£¨3£©¸ù¾ÝÏàËÆÈý½ÇÐεÄÅж¨ÓëÐÔÖÊ£¬¿ÉµÃMµã×ø±ê£¬¸ù¾ÝƽÐÐËıßÐεÄÐÔÖÊ£¬¿ÉµÃ´ð°¸£®
½â´ð ½â£º£¨1£©ÉèCµã×ø±êΪ£¨m£¬2m-2£©£¬
µ±y=0ʱ£¬2x-2=0£¬½âµÃx=1£¬¼´A£¨1£¬0£©£¬
ÓÉAC=2$\sqrt{5}$£¬µÃ
£¨m-1£©2+£¨2m-2£©2=£¨2$\sqrt{5}$£©2£¬
½âµÃm=3£¬m=-1£¨Éᣩ£¬2m-2=4£¬¼´C£¨3£¬4£©£¬
½«A£¬Cµã×ø±ê´úÈ뺯Êý½âÎöʽ£¬µÃ
$\left\{\begin{array}{l}{9a+3b-8=4}\\{a+b-8=0}\end{array}\right.$£¬
½âµÃ$\left\{\begin{array}{l}{a=-2}\\{b=10}\end{array}\right.$£¬
Å×ÎïÏߵĽâÎöʽΪy=-2x2+10x-8£»
£¨2£©Åä·½£¬µÃ
y=-2£¨x-$\frac{5}{2}$£©2+$\frac{9}{2}$
¼´E£¨$\frac{5}{2}$£¬$\frac{9}{2}$£©£®
µ±y=0ʱ£¬=-2x2+10x-8=0£¬½âµÃx=1£¨Éᣩx=4£¬¼´Dµã×ø±êΪ£¨4£¬0£©£¬
Èçͼ2ÖУ¬×÷D¹ØÓÚÖ±ÏßACµÄ¶Ô³ÆµãD¡ä£¬Á¬½ÓDD¡ä½»ACÓÚH£¬Á¬½ÓDEÓÉ´ËDE½»CCÓÚP£¬´Ëʱ|PD-EP|µÄÖµ×î´ó£®
¡ßÖ±ÏßDD¡äµÄ½âÎöʽΪy=-$\frac{1}{2}$x+2£¬
ÓÉ$\left\{\begin{array}{l}{y=-\frac{1}{2}x+2}\\{y=2x-2}\end{array}\right.$¿ÉµÃH£¨$\frac{8}{5}$£¬$\frac{6}{5}$£©£¬
¡àD¡ä£¨-$\frac{4}{5}$£¬$\frac{12}{5}$£©£¬
¡àÖ±ÏßD¡äEµÄ½âÎöʽΪy=$\frac{7}{11}$x+$\frac{32}{11}$£¬
ÓÉ$\left\{\begin{array}{l}{y=\frac{7}{11}x+\frac{32}{11}}\\{y=2x-2}\end{array}\right.$¿ÉµÃP£¨$\frac{18}{5}$£¬$\frac{26}{5}$£©£¬
´Ëʱ|PD-PE|µÄ×î´óÖµ=D¡äE=$\sqrt{£¨\frac{18}{5}-\frac{5}{2}£©^{2}-£¨\frac{26}{5}-\frac{9}{2}£©^{2}}$=$\frac{\sqrt{170}}{10}$£®
£¨3£©Èçͼ1
£¬
µ±y=0ʱ£¬2x-2=0£¬½âµÃx=1£¬¼´D£¨1£¬0£©£¬
¡ß¡Ï1+¡Ï2=90¡ã£¬¡Ï2+¡Ï3=90¡ã£¬
¡à¡Ï1=¡Ï3£¬
ÓÖ¡ß¡ÏBOD=¡ÏMOB£¬
¡à¡÷BOD¡×¡÷MOB£¬
¡à$\frac{MO}{BO}$=$\frac{BO}{OD}$£¬
½âµÃMO=4£¬¼´M£¨-4£¬0£©£¬
ÓɶԽÇÏßƽ·Ö£¬µÃ
$\frac{{x}_{N}+{x}_{B}}{2}$=$\frac{{x}_{M}+{x}_{C}}{2}$£¬¼´$\frac{{x}_{N}+0}{2}$=$\frac{-4+3}{2}$£¬¼´xN=-1£¬
$\frac{{y}_{N}+{y}_{B}}{2}$=$\frac{{y}_{M}+{y}_{C}}{2}$£¬¼´$\frac{{y}_{N}+£¨-2£©}{2}$=$\frac{0+4}{2}$£¬¼´yN=6£¬
Nµã×ø±êΪ£¨-1£¬6£©£»
Èçͼ2£¬
×÷CE¡ÍOMÓÚE£¬OE=3£¬CE=4£®
µ±y=0ʱ£¬2x-2=0£¬½âµÃx=1£¬¼´D£¨1£¬0£©£¬
DE=OE-OD=3-1=2£®
¡ß¡Ï1+¡Ï2=90¡ã£¬¡Ï2+¡Ï3=90¡ã£¬
¡à¡Ï1=¡Ï3£¬
ÓÖ¡ß¡ÏDEC=¡ÏCEM£¬
¡à¡÷DEC¡×¡÷CEM£¬
¡à$\frac{DE}{CE}$=$\frac{CE}{EM}$£¬
½âµÃME=8£¬¼´M£¨11£¬0£©£¬
ÓɾØÐεĶԽÇÏßƽ·Ö£¬µÃ
$\frac{{x}_{N}+{x}_{B}}{2}$=$\frac{{x}_{M}+{x}_{C}}{2}$£¬¼´$\frac{{x}_{N}+{x}_{C}}{2}$=$\frac{{x}_{B}+{x}_{M}}{2}$£¬$\frac{{x}_{N}+3}{2}$=$\frac{0+11}{2}$£¬¼´xN=8£¬
$\frac{{y}_{N}+{y}_{C}}{2}$=$\frac{{y}_{B}+{y}_{M}}{2}$£¬¼´$\frac{{y}_{N}+4}{2}$=$\frac{-2+0}{2}$£¬¼´yN=-6£¬
Nµã×ø±êΪ£¨8£¬-6£©£®
×ÛÉÏËùÊö£ºÈôµãMΪxÖáÉÏÒ»µã£¬µãNΪƽÃæÄÚÒ»µã£¬ÇÒÂú×ãÒÔµãB¡¢C¡¢M¡¢NΪ¶¥µãµÄËıßÐÎÊǾØÐΣ¬µãNµÄ×ø±ê£¨8£¬-6£©»ò£¨-1£¬6£©£®
µãÆÀ ±¾Ì⿼²éÁ˶þ´Îº¯Êý×ÛºÏÌ⣬½â£¨1£©µÄ¹Ø¼üÊÇÀûÓÃÁ½µãÖ®¼äµÄ¾àÀëµÃ³öCµã×ø±ê£¬ÓÖÀûÓôý¶¨ÏµÊý·¨£»½â£¨2£©µÄ¹Ø¼üÊÇÁ½±ßÖ®²îСÓÚµÚÈý±ßµÃ³öPÊÇDEÓëACµÄ½»µã£»½â£¨3£©µÄ¹Ø¼üÊÇÀûÓÃÏàËÆÈý½ÇÐεÄÅж¨ÓëÐÔÖʵóöMµãµÄ×ø±ê£¬ÓÖÀûÓÃÁ˾ØÐεÄÐÔÖÊ£®
Ä꼶 | ¸ßÖÐ¿Î³Ì | Ä꼶 | ³õÖÐ¿Î³Ì |
¸ßÒ» | ¸ßÒ»Ãâ·Ñ¿Î³ÌÍƼö£¡ | ³õÒ» | ³õÒ»Ãâ·Ñ¿Î³ÌÍƼö£¡ |
¸ß¶þ | ¸ß¶þÃâ·Ñ¿Î³ÌÍƼö£¡ | ³õ¶þ | ³õ¶þÃâ·Ñ¿Î³ÌÍƼö£¡ |
¸ßÈý | ¸ßÈýÃâ·Ñ¿Î³ÌÍƼö£¡ | ³õÈý | ³õÈýÃâ·Ñ¿Î³ÌÍƼö£¡ |
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
A£® | S=80-5x | B£® | S=5x | C£® | S=10x | D£® | S=5x+80 |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
A£® | a6¡Âa3=a2 | B£® | $\sqrt{6}$¡Â$\sqrt{3}$=$\sqrt{2}$ | C£® | £¨-1£©-1=1 | D£® | £¨a3£©2=a5 |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
A£® | 2000Ãû¿¼ÉúÊÇ×ÜÌåµÄÒ»¸öÑù±¾ | |
B£® | ÿ¸ö¿¼ÉúÊǸöÌå | |
C£® | Õâ5ÍòÃû¿¼ÉúµÄÊýѧÖп¼³É¼¨µÄÈ«ÌåÊÇ×ÜÌå | |
D£® | ͳ¼ÆÖвÉÓõĵ÷²é·½Ê½ÊÇÆÕ²é |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
A£® | 180¡ã | B£® | 360¡ã | C£® | 720¡ã | D£® | 1080¡ã |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
A£® | £¨1£¬6£© | B£® | £¨6£¬1£© | C£® | £¨6£¬0£© | D£® | £¨7£¬2£© |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
A£® | B£® | C£® | D£® |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º³õÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
A£® | 163¡Á103 | B£® | 16.3¡Á104 | C£® | 1.63¡Á105 | D£® | 0.163¡Á106 |
²é¿´´ð°¸ºÍ½âÎö>>
°Ù¶ÈÖÂÐÅ - Á·Ï°²áÁбí - ÊÔÌâÁбí
ºþ±±Ê¡»¥ÁªÍøÎ¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨Æ½Ì¨ | ÍøÉÏÓк¦ÐÅÏ¢¾Ù±¨×¨Çø | µçÐÅթƾٱ¨×¨Çø | ÉæÀúÊ·ÐéÎÞÖ÷ÒåÓк¦ÐÅÏ¢¾Ù±¨×¨Çø | ÉæÆóÇÖȨ¾Ù±¨×¨Çø
Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com