0  356860  356868  356874  356878  356884  356886  356890  356896  356898  356904  356910  356914  356916  356920  356926  356928  356934  356938  356940  356944  356946  356950  356952  356954  356955  356956  356958  356959  356960  356962  356964  356968  356970  356974  356976  356980  356986  356988  356994  356998  357000  357004  357010  357016  357018  357024  357028  357030  357036  357040  357046  357054  447090 

2.(2010哈尔滨)如图,在平面直角坐标系中,点O是坐标原点,四边形AOCB是梯形,AB∥OC,点A的坐标为(0,8),点C的坐标为(10,0),OB=OC.

  (1)求点B的坐标;

  (2)点P从C点出发,沿线段CO以5个单位/秒的速度向终点O匀速运动,过点P作PH⊥OB,垂足为H,设△HBP的面积为S(S≠0),点P的运动时间为t秒,求S与t之间的函数关系式(直接写出自变量t的取值范围);

   (3)在(2)的条件下,过点P作PM∥CB交线段AB于点M,过点M作MR⊥OC,垂足为R,线段MR分别交直线PH、OB于点E、G,点F为线段PM的中点,连接EF,当t为何值时,

 (2010台州市)   22.类比学习:一动点沿着数轴向右平移3个单位,再向左平移2个单位,相当于向右平移1个单位.用实数加法表示为 3+()=1.

    若坐标平面上的点作如下平移:沿x轴方向平移的数量为a(向右为正,向左为负,平移个单位),沿y轴方向平移的数量为b(向上为正,向下为负,平移个单位),则把有序数对{ab}叫做这一平移的“平移量”;“平移量”{ab}与“平移量”{cd}的加法运算法则为

   解决问题:(1)计算:{3,1}+{1,2};{1,2}+{3,1}.

  (2)①动点P从坐标原点O出发,先按照“平移量”{3,1}平移到A,再按照“平移量”

{1,2}平移到B;若先把动点P按照“平移量”{1,2}平移到C,再按照“平移量”

{3,1}平移,最后的位置还是点B吗? 在图1中画出四边形OABC.

②证明四边形OABC是平行四边形.

(3)如图2,一艘船从码头O出发,先航行到湖心岛码头P(2,3),再从码头P航行到码头Q(5,5),最后回到出发点O. 请用“平移量”加法算式表示它的航行过程.

 

解:(1){3,1}+{1,2}={4,3}.  ……………………………………………2分

{1,2}+{3,1}={4,3}. …………………………………………………………………2分

(2)①画图 …………………………………………………2分

   最后的位置仍是B.……………………………………1分

② 证明:由①知,A(3,1),B(4,3),C(1,2)

OC=AB==OA=BC==

  ∴四边形OABC是平行四边形.…………………………3分

(3){2,3}+{3,2}+{-5,-5}={0, 0}.……………………2分

试题详情

1.(2010哈尔滨)如图,在△ABC中,∠ACB=90°,AC=BC=10,在△DCE中,

∠DCE=90°,DC=EC=6,点D在线段AC上,点E在线段BC

的延长线上.将△DCE绕点C旋转60°得到△D′CE′(点D的

对应点为点D′,点E的对应点为点 E′),连接AD′、BE′,

过点C作CN⊥ BE′,垂足为N,直线CN交线段AD′于点M,

则MN的长为          

试题详情

There are many types of reports. A report is simply an account of something 1  has happened. The commonest are news reports. We get them in newspapers,  2  the radio, and on television. The main purpose of a newspaper  3  (provide) news. If you examine a newspaper 4  (close), you will find that there are all types of news: accident, floods, fires, wars, fashions, sports, books, etc. The news  5  (cover) everything that happens to people and their surroundings. Sometimes there  6  (be) news items which are very amusing. A news report is usually very short, except  7   it is about something very important. It is also written in short paragraphs. The first paragraph is in fact  8  summary of the news item. The other paragraph give full details of the subject. There  9  (情态动词) also be interviews with people. Often there are photographs to 10  (动词短语) the news to make it more interesting.  K^S*5U.C#O

试题详情

10. He is said _____________(travel) around the country for 3 times.

试题详情

9. A cook will be immediately fired if he is found ____________(smoke) in the kitchen.

试题详情

8. So many people ______________(look) at her, she couldn’t speak out a single word.

试题详情

7. His attention ______________(fix) his own research work, he did not even notice the loudly noise around him.

试题详情

6. The criminal was about to tell the truth _______________ he was shot.

试题详情

5.________________(accept) as a member of the company, he took over the job of the former secretary.

试题详情

4. ________________(receive) her letter for a long time, I phoned her to see what was wrong.

试题详情


同步练习册答案