您所在的当前位置：高中数学试题 >

平面向量数量积的意义

> 在直角坐标平面上，向量 OA =(1，3)、 OB =(-3，1)（O为原点）在直线l上的射影长度相等，且直线l的倾斜角为锐角，则l的斜率等于（　　） A．1 B． 3 2 C． 1 2 D． 3 3

问题：

发布时间：2024-09-13

在直角坐标平面上，向量

OA

=(1，3)、

OB

=(-3，1)（O为原点）在直线l上的射影长度相等，且直线l的倾斜角为锐角，则l的斜率等于（　　）

A．1 B．

3

2

C．

1

2

D．

3

3

参考答案：

提问用户：L5***ynl

可能感兴趣的题目：

1 执行程序框图，如果输入的n是5，则输出的p是（　　） A．1 B．2 C．3 D．5
2 下表是我国南、北方水土资源比例表。据表回答。 A.南方水多地少　　 B.南方水少地多 C.北方水多地少　　 D.北方水少地少
3 阅读理解。 It was early afternoon and the harbor (海港) was quiet. Mr Bates, the keeper of the lighthouse (灯塔), went to the village. He left his daughters Rebecca and Abigail to look after the lighthouse. As Rebecca was about to prepare some water for the evening meal, she noticed a strange ship coming to the harbor. It stopped and lowered two little boats, which turned and started toward land: At that time people feared every ship they did not know, for the year was 1814 and America and Britain were at war. Rebecca and Abigail held their breath to see what these two boats would do. Closer and closer they came, until finally they entered the harbor. They were full of British soldiers! No help was to be seen. What could they do? How could they warn the town soldiers? They had no boat, and there would be no time to run to the village. Rebecca thought fast and then she had an idea. Calling to Abigail to follow, she ran to the room where the guns were stored. But instead of reaching for the guns, she took hold of the fife (军笛 ) and the drum(战鼓 ). Then the two young women ran along the wooded path to the shore (海岸). Hiding behind tall trees, they started to play the fife and the drum. Abigail beat out Roll Call. Rebecca joined in with Yankee Doodle. Soon Rebecca saw the boats had stopped! The girls went on playing. A moment later, a flag was raised on the warship-the signal for the boats to return. Once everyone was on board, the enemy ship set sail for the open sea. The British were fooled, and the" American Army of Two" won the day. 1. Why did Rebecca take the fife and the drum instead of the guns? A. She would leave the guns for the soldiers. B. She would welcome the British soldiers. C. She loved to play the fife and the drum. D. She wanted to frighten the British soldiers away. 2. The underlined part " American Army of Two" in the last paragraph probably refers to____. A. Rebecca and Abigail B. the two British boats C. the fife and the drum D. the two town soldiers 3. The British ship left the harbor because____. A. the British found the weather was too bad B. a lot of American ships came to stop the British C. the British thought the American soldiers were coming D. some of the British soldiers were killed by the American 4. Which of the following words could NOT be used to describe Rebecca and Abigail"s action?____ A. Brave. B. Honest. C. Clever. D. Great.
4 在指定条件下，下列各组离子可能大量共存的是 [ ] A．某透明的酸性溶液中：Cl -、Na +、MnO 4 -、SO 4 2- B．水电离产生的c(H +)为10 -12 mol．L -1的溶液中：K +、CO 3 2-、Cl -、NO 3 - C．在加入铝能产生氢气的溶液中：Na +、NH 4 +、I -、NO 3 - D．能使pH试纸变红色的溶液中：Na +、AlO 2 -、K +、CO 3 2-
5 Personally, I think it’s your attitude, rather than your score, ______ matters in your study. A．which B．that C．how D．what
6 下列各图中阴影部分表示某种气候条件下分布的某种农作物。其序号与下列农作物排序一致的是 A．春小麦玉米水稻冬小麦 B．水稻春小麦玉米冬小麦 C．甘蔗甜菜咖啡亚麻 D．咖啡橡胶甘蔗甜菜
7 When I heard the news that she was going to resign, I was surprised. I was astonished. A．more than B．less than C．other than D．rather than
8 0.1 mol某元素M的单质直接与氯气反应后，消耗Cl 2 3.55 g，这种元素是( ) A．Na B．Mg C．Fe D．H2
9 信息匹配。阅读应用文和相关信息，并按照要求匹配信息。 Two men on a touring holiday in Britain were injured by an explosion (爆炸) in their motor truck in the center of Norwich yesterday. 1 Several people rushed to give help and helped to put out the fire inside the truck. A light American bus rushed to save drivers before Norwich firemen arrived. The men-American Mr Gary House, aged 25,of Ohio, who was Driving,and his passenger Mr Charles Lynn,23,of Vancouver were taken to Norfolk and Norwich Hospital with minor(轻微的)burns. 2 "I heard this explosion. It was pretty loud. I thought it could have been a bomb." said Mr Leslie Webster, manager of the market, who was working in his office in Red Lion Street."I looked out of the window and saw this man jump from the truck and roll on the ground. Then another man came out of the truck. 3 "I came downstairs to get a fire extinguisher (灭火器),but by the time I got outside, someone who came from the bank. was in the truck with an extinguisher." 4 One was taken into the market office to await treatment. "The second man insisted on going back into the truck to see if everything was all right, and five minutes later he came out with a drawer that was burning," he added. The explosion was also heard inside the bank. Office workers provided afire extinguisher and telephoned for medical help. Although a window was blown out, damage inside the truck was mainly superficial (表面的). The two men spent the last six months touring the Continent and had traveled to Norwich from Shettertor. 5 A. They were allowed to leave after treatment. B. Mr Webster, who lives at 71,Trinity Street, Norwich, said both the two injured were shocked. C. At the time of the accident their wives were shopping in the city. D. Shoppers and businessman in Red Lion Street were shocked by a loud bang (突然巨响), and seconds later the two men jumped over from the truck, which had stopped outside Barelays bank. E. Their wives were traveling with them but they remained unburned. F. He seemed to be in a worse state, parts of his trousers were hanging below his knees.
10 下列各种情况下，溶液中一定能大量共存的离子组是 [ ] A．由水电离出的c(H +) =1×10 -12 mol·L -1的溶液中：K +、Ba 2+、AlO 2 -、NO 3 - B．澄清透明的溶液中：I -、Cl -、ClO -、Na + C．使pH试纸呈红色的溶液中：K +、Fe 2+、NO 3 -、MnO 4 - D．含有S 2O 3 2-的溶液中：K +、Na +、SO 3 2-、SO 4 2-

在直角坐标平面上，向量 OA =(1，3)、 OB =(-3，1)（O为原点）在直线l上的射影长度相等，且直线l的倾斜角为锐角，则l的斜率等于（ ） A．1 B． 3 2 C． 1 2 D． 3 3

可能感兴趣的题目：

在直角坐标平面上，向量

OA

=(1，3)、

OB

=(-3，1)（O为原点）在直线l上的射影长度相等，且直线l的倾斜角为锐角，则l的斜率等于（　　）

A．1 B．

3

2

C．

1

2

D．

3

3