19£®ÒÑÖªÍÖÔ²CµÄÖÐÐÄÔÚ×ø±êÔ­µã£¬½¹µãÔÚxÖáÉÏÇÒ¹ýµã$P£¨1£¬-\frac{3}{2}£©$£¬ÀëÐÄÂÊÊÇ$\frac{1}{2}$£®
£¨1£©ÇóÍÖÔ²µÄ±ê×¼·½³Ì£»
£¨2£©¹ýÍÖÔ²ÉÏÈÎÒâÒ»µãP×÷Ô²O£ºx2+y2=3µÄÇÐÏßl1£¬l2£¬ÉèÖ±ÏßOP£¬l1£¬l2µÄбÂÊ·Ö±ðÊÇk0£¬k1£¬k2£¬ÊÔÎÊÔÚÈý¸öбÂʶ¼´æÔÚÇÒ²»Îª0µÄÌõ¼þÏ£¬$\frac{1}{k_0}£¨\frac{1}{k_1}+\frac{1}{k_2}£©$ÊÇ·ñÊǶ¨Öµ£¬Çë˵Ã÷ÀíÓÉ£¬²¢¼ÓÒÔÖ¤Ã÷£®

·ÖÎö £¨1£©Éè³öÍÖÔ²·½³Ì£¬ÀûÓÃÒÑÖªÌõ¼þÁгö·½³Ì×飬Çó³öa£¬b£¬¼´¿ÉµÃµ½ÍÖÔ²·½³Ì£®
£¨2£©ÉèP£¨x0£¬y0£©£¬¹ýPµÄбÂÊΪkµÄÖ±ÏßΪy-y0=k£¨x-x0£©£¬ÀûÓÃÖ±ÏßÓëÔ²OÏàÇÐÍÆ³ö$£¨{x_0}^2-3£©{k^2}-2{x_0}{y_0}k+{y_0}^2-3=0$£¬Í¨¹ýΤ´ï¶¨ÀíµÃµ½$\frac{1}{k_1}+\frac{1}{k_2}=\frac{{2{x_0}{y_0}}}{{{y_0}^2-3}}$£¬´úÈë${y_0}^2-3=-\frac{3}{4}{x_0}^2$£¬ÍƳö½á¹û£®

½â´ð ½â£º£¨1£©ÉèÍÖÔ²CµÄ±ê×¼·½³ÌΪ$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1£¨a£¾b£¾0£©$£®
ÓÉÒÑÖª¿ÉµÃ$\left\{\begin{array}{l}{a^2}={b^2}+{c^2}\\ \frac{c}{a}=\frac{1}{2}\\ \frac{1}{a^2}+\frac{9}{{4{b^2}}}=1\end{array}\right.$£¬½âµÃa2=4£¬b2=3£®¹ÊÍÖÔ²CµÄ±ê×¼·½³ÌΪ$\frac{x^2}{4}+{y^2}=1$
£¨2£©ÉèP£¨x0£¬y0£©£¬¹ýPµÄбÂÊΪkµÄÖ±ÏßΪy-y0=k£¨x-x0£©£¬
ÓÉÖ±ÏßÓëÔ²OÏàÇпɵÃÏ£¬$\frac{{|y-k{x_0}|}}{{\sqrt{{k^2}+1}}}=\sqrt{3}$£¬¼´£º$£¨{x_0}^2-3£©{k^2}-2{x_0}{y_0}k+{y_0}^2-3=0$£¬
ÓÉÒÑÖª¿ÉÖªk1£¬k2ÊÇ·½³Ì$£¨{x_0}^2-3£©{k^2}-2{x_0}{y_0}k+{y_0}^2-3=0$µÄÁ½¸ö¸ù£¬
ËùÒÔÓÉΤ´ï¶¨Àí£ºk1+k2=$\frac{{2{x_0}{y_0}}}{{{x_0}^2-3}}$£¬k1k2=$\frac{{{y_0}^2-3}}{{{x_0}^2-3}}$£¬
Á½Ê½Ïà³ý£º$\frac{1}{k_1}+\frac{1}{k_2}=\frac{{2{x_0}{y_0}}}{{{y_0}^2-3}}$£¬
ÓÖÒòΪ${y_0}^2-3=-\frac{3}{4}{x_0}^2$£¬
´úÈëÉÏʽ¿ÉµÃ£¬$\frac{1}{k_0}£¨\frac{1}{k_1}+\frac{1}{k_2}£©=-\frac{8}{3}$Ϊһ¸ö¶¨Öµ£®

µãÆÀ ±¾Ì⿼²éÍÖÔ²·½³ÌµÄÇó·¨ÔÚÏÂÓêÔ²µÄλÖùØÏµÒÔ¼°ÍÖÔ²·½³ÌµÄ×ÛºÏÓ¦Ó㬿¼²éת»¯Ë¼ÏëÒÔ¼°¼ÆËãÄÜÁ¦£®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

2£®ÏÂÁÐ˵·¨£º
¢Ù½«Ò»×éÊý¾ÝÖеÄÿ¸öÊý¾Ý¶¼¼ÓÉÏ»ò¼õȥͬһ¸ö³£Êýºó£¬¾ùÖµÓë·½²î¶¼²»±ä£»
¢ÚÉèÓÐÒ»¸ö»Ø¹é·½³Ì$\widehaty=5-3x$£¬±äÁ¿xÔö¼ÓÒ»¸öµ¥Î»Ê±£¬yƽ¾ùÔö¼Ó3¸öµ¥Î»£»
¢ÛÏßÐԻع鷽³Ì$\widehaty=bx+a$±Ø¾­¹ýµã$£¨\overline x£¬\overline y£©$£»
¢ÜÔÚÎüÑÌÓ뻼·Î²¡ÕâÁ½¸ö·ÖÀà±äÁ¿µÄ¼ÆËãÖУ¬´Ó¶ÀÁ¢ÐÔ¼ìÑéÖª£¬ÓÐ99%µÄ°ÑÎÕÈÏΪÎüÑÌÓ뻼·Î²¡ÓйØÏµÊ±£¬ÎÒÃÇ˵ÏÖÓÐ100ÈËÎüÑÌ£¬ÄÇôÆäÖÐÓÐ99ÈË»¼·Î²¡£®ÆäÖдíÎóµÄ¸öÊýÊÇ£¨¡¡¡¡£©
A£®0B£®1C£®2D£®3

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

3£®Ä³¹¤³§Éú²úA¡¢B¡¢CÈýÖÖ²»Í¬ÐͺŵIJúÆ·£¬²úÆ·ÊýÁ¿Ö®±ÈÒÀ´ÎΪk£º5£º3£¬ÏÖÓ÷ֲã³éÑù·½·¨³é³öÒ»¸öÈÝÁ¿Îª120µÄÑù±¾£¬ÒÑÖªAÖÖÐͺŲúÆ·¹²³éÈ¡ÁË24¼þ£¬ÔòCÖÖÐͺŲúÆ·³éÈ¡µÄ¼þÊýΪ36£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

7£®1 624Óë899µÄ×î´ó¹«Ô¼ÊýÊÇ29£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

14£®É躯Êýf£¨x£©=$\sqrt{{x}^{2}+1}$-2x£¬Ö¤Ã÷£ºº¯Êýf£¨x£©ÔÚÇø¼ä[0£¬+¡Þ£©ÉÏÊǼõº¯Êý£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

4£®Èôº¯Êý$f£¨x£©=\left\{{\begin{array}{l}{a£¨x-1£©+1£¬x£¼-1}\\{{a^{-x}}£¬x¡Ý-1}\end{array}£¬£¨a£¾0}\right.$£¬ÇÒ£¨a¡Ù1£©ÊÇRÉϵĵ¥µ÷º¯Êý£¬ÔòʵÊýaµÄȡֵ·¶Î§£¨¡¡¡¡£©
A£®£¨0£¬$\frac{1}{3}$£©B£®£¨$\frac{1}{3}$£¬1£©C£®£¨0£¬$\frac{1}{3}$]D£®[$\frac{1}{3}$£¬1£©

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

11£®ÒÑÖªº¯Êýf£¨x£©=$\frac{{a}^{x}-1}{{a}^{x}+1}$£¨a£¾0ÇÒa¡Ù1£©
£¨¢ñ£©ÅжϺ¯Êýf£¨x£©µÄÆæÅ¼ÐÔ£¬²¢¼ÓÒÔÖ¤Ã÷£»
£¨¢ò£©Çóf£¨x£©µÄÖµÓò£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

8£®ÏÂÁк¯ÊýÖУ¬Ææº¯ÊýÊÇ£¨¡¡¡¡£©
A£®f£¨x£©=sin|x|B£®f£¨x£©=xsinxC£®y=£¨$\sqrt{x}$£©2D£®y=2x-2-x

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

9£®ÒÑÖªº¯Êýf£¨x£©=Asin£¨¦Øx+¦Õ£©£¨A£¾0£¬¦Ø£¾0£¬|¦Õ|£¼$\frac{¦Ð}{2}$£©µÄ²¿·ÖͼÏóÈçͼËùʾ£®
£¨1£©Çóº¯Êýf£¨x£©µÄ½âÎöʽ£»
£¨2£©½«y=f£¨x£©Í¼ÏóÉÏËùÓеãÏòÓÒÆ½ÒÆ$\frac{¦Ð}{6}$¸öµ¥Î»³¤¶È£¬µÃµ½y=g£¨x£©µÄͼÏó£¬Çóy=g£¨x£©µÄͼÏóÀëÔ­µãO×î½üµÄ¶Ô³ÆÖÐÐÄ£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸