利用一次函数图象上点的坐标特征,求出一次函数的解析式;分别求出直线经过点,点时的值,即可得到的取值范围;找出点关于直线在坐标轴上的对称点,,如解答图所示.求出点,的坐标,然后分别求出,中点坐标,最后分别求出时间的值.
解:直线交轴于点,由题意,得,,.当时,,故.当直线过点时,,解得:,,解得.当直线过点时,,解得:,,解得.故若点,位于的异侧,的取值范围是:.如右图,过点作直线,交轴于点,交轴于点,则点,为点在坐标轴上的对称点.过点作轴于点,则,.已知,则与均为等腰直角三角形,,,,.,,线段中点坐标为.直线过点,则,解得:,,解得.,,线段中点坐标为.直线过点,则,解得:,,解得.故点关于的对称点,当时,落在轴上,当时,落在轴上.
本题是动线型问题,考查了坐标平面内一次函数的图象与性质.难点在于第问,首先注意在轴,轴上均有点的对称点,不要漏解;其次注意点,坐标以及线段中点坐标的求法.
3804@@3@@@@一次函数综合题@@@@@@253@@Math@@Junior@@$253@@2@@@@一次函数@@@@@@51@@Math@@Junior@@$51@@1@@@@函数@@@@@@7@@Math@@Junior@@$7@@0@@@@初中数学@@@@@@-1@@Math@@Junior@@
第三大题，第4小题
第三大题，第3小题
求解答 学习搜索引擎 | 如图,A(0,1),M(3,2),N(4,4).动点P从点A出发,沿y轴以每秒1个单位长的速度向上移动,且过点P的直线l:y=-x+b也随之移动,设移动时间为t秒.(1)当t=3时,求l的解析式;(2)若点M,N位于l的异侧,确定t的取值范围;(3)直接写出t为何值时,点M关于l的对称点落在坐标轴上.求解答，_百度知道
那个新人才来几天对我这方面一点都不会，，并且说是另外补钱给我公司要把我调到生产车间做事说是临时的等招到人再回来，并且让一个有点关系的新人代替我，
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出门在外也不愁根据条件求出的坐标,利用直线的斜率为,建立关于,的方程即可求的离心率;根据直线在轴上的截距为,以及,建立方程组关系,求出的坐标,代入椭圆方程即可得到结论.
解:是上一点且与轴垂直,的横坐标为,当时,,即,若直线的斜率为,即,即,即,则,解得.()由题意,原点是的中点,则直线与轴的交点是线段的中点,故,即,由,解得,设,由题意知,则,即代入椭圆方程得,将代入得,解得,.
本题主要考查椭圆的性质,利用条件建立方程组,利用待定系数发是解决本题的关键,综合性较强,运算量较大,有一定的难度.
2235@@3@@@@椭圆的应用@@@@@@164@@Math@@Senior@@$164@@2@@@@圆锥曲线与方程@@@@@@31@@Math@@Senior@@$31@@1@@@@平面解析几何@@@@@@4@@Math@@Senior@@$4@@0@@@@高中数学@@@@@@-1@@Math@@Senior@@
第三大题，第4小题
第三大题，第4小题
第三大题，第4小题
第三大题，第4小题
第三大题，第5小题
求解答 学习搜索引擎 | 设{{F}_{1}},{{F}_{2}}分别是C:\frac{{{x}^{2}}}{{{a}^{2}}}+\frac{{{y}^{2}}}{{{b}^{2}}}=1(a>b>0)的左,右焦点,M是C上一点且M{{F}_{2}}与x轴垂直,直线M{{F}_{1}}与C的另一个交点为N.(1)若直线MN的斜率为\frac{3}{4},求C的离心率;(2)若直线MN在y轴上的截距为2,且|MN|=5|{{F}_{1}}N|,求a,b.第三方登录：求解答过程：阅读理解.
Bamboo (竹子) is one of nature's (自然) most surprising plants. Many people call this plant a tree, but it is a kind of grass.
Like other kinds of grass, a bamboo plant may be cut very_百度作业帮
求解答过程：阅读理解.
Bamboo (竹子) is one of nature's (自然) most surprising plants. Many people call this plant a tree, but it is a kind of grass.
Like other kinds of grass, a bamboo plant may be cut very
求解答过程：阅读理解.
&&&& Bamboo (竹子) is one of nature's (自然) most surprising plants. Many people call this plant a tree, but it is a kind of grass.
&&&& Like other kinds of grass, a bamboo plant may be cut very low to the ground, but it will grow back very
quickly. A Japanese scientist reported one bamboo plant which grew 1. 5 meters (4 feet) in 24 hours! Bamboo grows almost everywhere in the world except Europe. There are more than 1, 000 kinds of bamboo.
&&&& Not all bamboo looks the same. Some bamboo plants are very thin. They may only grow to be a few
centimeters wide while others may grow to more than 30 centimeters (1 foot) across. This plant also comes in different colors, from yellow to black to green.
&&&& Bamboo has been used to make many things such as hats and kitchen tools ( 厨房用具). Because it is strong, bamboo is also used to build buildings.
&&&& Many Asian countries have used bamboo for hundreds of years. They often use bamboo for buildings
and supporting (支撑) new buildings and bridges while they are being built.
&&&&& In Africa, poor farmers are taught how to find water using bamboo. These African countries need cheap way to find water because they have no money, and their fields often die from no rain and no water. Bamboo pipes ( 管子) help poor farmers bring water to their thirsty fields without spending a lot of money.
1. How is bamboo like grass?
A. It grows quickly.
B. It's wood.
C. it is easy to cut.
D. It is very thin.
2. Though you can see bamboo everywhere, it doesn't grow _____.
A. in China
B. in Europe
C. on mountains D. in Africa
3. Why is bamboo used by African poor farmers? Because _____.
A. it is cheap B. it has different colors
C. it is strong
D. it has been used by Asians
4. Bamboo pipes can _____.
A. make money B. be trees C. grow quickly
D. carry water
5. In Asia, bamboo has been used for _____.
A. a short time
B. many thousands of years C. many hundreds of years
D. about 100 years
1-5& ACADB}