您所在的当前位置：高中数学试题 >

任意角三角函数的概念

> 有一长为1公里的斜坡，它的倾斜角为20°，现要将倾斜角改为10°，则坡底要伸长（　　） A．1公里 B．sin10°公里 C．cos10°公里 D．cos20°公里

问题：

发布时间：2024-09-09

有一长为1公里的斜坡，它的倾斜角为20°，现要将倾斜角改为10°，则坡底要伸长（　　）

A．1公里 B．sin10°公里 C．cos10°公里 D．cos20°公里

参考答案：

提问用户：aI***Knh

可能感兴趣的题目：

1 一月年等温线中秦岭-淮河一线的温度是 A.-10℃ B.10℃ C.0℃ D.以上答案都不对
2 秦岭--淮河以北枣树成林，以南橘香满园，这是因为 A.气候不同 B.地形不同 C.耕作制度不同 D.栽培技术不同
3 --- What are you going to do tomorrow? --- I will go _____ with my friends on the lake. A．hunting B．shopping C．shipping D．boating
4 This is Tom, Mary. ________. A.I am Mary B.I know that C.How are you D.Nice to meet you
5 阅读理解。 Some people are lucky enough to be born with a good sense of direction and even if they have only visited a place once, they will be able to find it again years later. 　 I am one of those unfortunate people who have poor sense of direction and I may have visited a place time after time but I still get lost on my way there. When I was young I was so shy that I never dared ask complete strangers the way and so I used to wander round in circles and hope that by some chance I would get to the spot I was heading for. 　 I am no longer too shy to ask people for direction, but I often receive replies that puzzle me. Often people do not like to admit that they didn"t know their hometown and will insist on telling you the way, even if they do not know it; others, who are anxious to prove that they know their hometown very well, will give you a long list of directions which you can not possibly hope to remember, and still others do not seem to be able to tell between their left and their right and you find in the end that you are going in the opposite direction. 　 If anyone ever asks me the way to somewhere, I always tell them I am a stranger to the town in order to avoid giving them wrong direction but even this can have embarrassing results. 　 Once I was on my way to work when I was stopped by a man who asked me if I would direct him the way to the Sunlight Building. I gave my usual reply, but I had not walked on a few steps when I realized that he had asked for directions to my office building. However, at this point, I decide it was too late to turn back and search for him out of the crowd behind me as I was going to meet with someone at the office and I did not want to keep him waiting. 　 Imagine my embarrassment when my secretary showed in the very man who had asked for directions to my office and his astonishment when he recognized me as the person he had asked. 1. What is the writer going to do when someone asks him for direction? A. He will direct the right way to the person willingly. B. He will reply to it by the means of being a stranger to the town. C. He will give the very person long list of direction. D. He is going to show the man an opposite direction. 2. How did the visitor feel when he was showed into the very room? A. He felt strange. B. He felt embarrassed. C. He felt very sad. D. He felt astonished. 3. Who showed the right way to the interviewee according to the passage? A. Someone we don"t know. B. The writer did it for himself. C. The secretary did so. D. A warm-hearted old lady did such a thing.
6 在下列给定条件的各溶液中，一定能大量共存的离子组是 [ ] A．含有0.1 mol/L Fe 3+的溶液中：K +、Mg 2+、I -、NO 3 - B．室温下，pH=1的溶液中：Na +、Fe 3+、NO 3 -、SO 4 2- C．加入Al能放出H 2的溶液中：NH 4 +、SO 4 2-、Cl -、HCO 3 - D．由水电离的c(OH -)=10 -13 mol/L的溶液中：Ba 2+、Cu 2+、Cl -、NO 3 -
7 Can you help me ________? A.anymore B.some more C.any more D.more
8 （10分）元素氯及其化合物在生产、生活、科研中有广泛的应用。 ⑴25℃时，PbCl 2固体在不同浓度盐酸(mol·L － 1)中的溶解度(mmol·L － 1)如图。 ①在制备PbCl 2的实验中，洗涤PbCl 2固体最好选用。 a．蒸馏水 b．1mol·L － 1盐酸 c．5 mol·L － 1盐酸 d．10mol·L － 1盐酸 ②当盐酸的浓度小于1mol·L － 1时，随着盐酸浓度的增大，PbCl 2 的溶解度减小，其原因是。 ⑵TCCA广泛用于漂白、杀菌消毒，其学名为三氯均三嗪-2,4,6-三酮，分子式为：C 3Cl 3N 3O 3。 ①TCCA分子具有完全对称的结构，并含有一个六元环，则其结构简式为。 ②使用TCCA时，需先将该物质溶解于水，其水解产物之一为C 3H 3N 3O 3，另一种产物具有强氧化性，能够杀菌消毒。写出另一种产物的电子式。 ⑶高氯酸铵(AP)作为一种优良的固体推进剂被用于导弹和火箭发射。目前，较为先进的制备方法是电解高纯次氯酸得到高纯高氯酸，再与高纯氨进行喷雾反应制成高氯酸铵。写出由次氯酸电解制备高氯酸的阳极反应式：。
9 下列数据不一定随着温度升高而增大的是 [ ] A．化学反应速率v B．弱电解质的电离平衡常数Ka C．化学平衡常数K D．水的离子积常数Kw
10 某无色透明的强酸性溶液中，能大量共存的一组离子是 [ ] A.NH 4 +、Na +、Cl -、SO 3 2- B.Mg 2+、Al 3+、SO 4 2-、NO 3 - C.Na +、K +、SO 4 2-、AlO 2 - D.K +、NH 4 +、MnO 4 -、Cl -

有一长为1公里的斜坡，它的倾斜角为20°，现要将倾斜角改为10°，则坡底要伸长（ ） A．1公里 B．sin10°公里 C．cos10°公里 D．cos20°公里

可能感兴趣的题目：

有一长为1公里的斜坡，它的倾斜角为20°，现要将倾斜角改为10°，则坡底要伸长（　　）

A．1公里 B．sin10°公里 C．cos10°公里 D．cos20°公里