这是一道平面直角坐标系的几何题,有图,怎么做?求解答?求完整证明过程,谢谢!28.如图1,在平面直角坐标系中,O为坐标原点,A（m,0)在x轴上,B(0,2m)在y轴上,若m为正整数,且m满足不等式 组
2m－8≥_百度作业帮
这是一道平面直角坐标系的几何题,有图,怎么做?求解答?求完整证明过程,谢谢!28.如图1,在平面直角坐标系中,O为坐标原点,A（m,0)在x轴上,B(0,2m)在y轴上,若m为正整数,且m满足不等式 组
这是一道平面直角坐标系的几何题,有图,怎么做?求解答?求完整证明过程,谢谢!28.如图1,在平面直角坐标系中,O为坐标原点,A（m,0)在x轴上,B(0,2m)在y轴上,若m为正整数,且m满足不等式 组
10－m／3＞0⑴求A、B两点坐标⑵如图1,点C为线段AB上一点,连接OC,且OC平分∠AOB,求点C的坐标⑶如图2,在⑵的条件下,点P在y轴上,点Q（a,﹣2a＋18）在线段AB上,若CP＝PQ,且∠CPQ＝90º,求a的值及点P的坐标
1解不等式组得到17/2
我是初二学生，能用简单方法做吗，看不懂您的方法，我们没有学斜率和tan，谢谢
定比分点学了吗？？向量学了吗？？
　　没。。。能做辅助线解决吗
2要不就这样求呗设C(t ,-2t+18)其中0<t<9然后BC=2AC根据两点间距离公式，所以√[t^2+(-2t+18-18)^2]=2√[(t-9)^2+(-2t+18-0)^2]然后两边平方，肯定求出两个t, 根据0<t<9，选其中一个t=6即可。3设CQ中点为M然后PM⊥CQ设PM的方程为y=x/2+b然后令x=0得到P(0,b)PM与直线AB联立求出M((36-2b)/5， (18+4b)5)根据CP=√2PM再次带入两点间的距离公式，√[6^2+(6-b)^2]=√2 √[(36-2b)/5]^2+[(18+4b)5-b]^2解出来b即可不懂可追问。很多定理公式没学过，就得用复杂点的计算来弥补了2中的方程解起来很简单。3中可能稍微麻烦点。
我想问一下10－m／3＞0是有没有小括号的，如果有，那是在哪里有（10－m）／3＞0(1)∵2m－8≥9
且 （10－m）／3＞0∴m≥8.5
m＜10∴m=9∴A(9,0)
B(0,18)(2)作CD⊥OA∴△CDA相似△BOA又∵OC平分∠AOB且CD⊥OA
∴△OCD为正三角形 ...
(1)∵2m－8≥9
且 （10－m）／3＞0∴m≥8.5
m＜10∴m=9∴A(9,0)
B(0,18)(2)作CD⊥OA∴△CDA相似△BOA又∵OC平分∠AOB且CD⊥OA
∴△OCD为正三角形
∴设DA为x，则OD为9-x ，∴CD=OD=9-x
∴x/9=(9-x)/18
∴C(6,6)(3)
我用了很多都算不出来，a没有答案
可是第三问是有答案的
虾米，你能把它写上来吗。因为我很久没有写过作业了啊，脑子有点秀逗了，嘻嘻
没有图怎么解有图，我再发一遍<img class="ikqb_img" src="http://f./zhidao/wh%3D600%2C800/sign=fb501f6fdaa1de43719c2/bd315c6034a85edfc01c861a4a7572.jpg" esrc="http://f....
由不等式组可得：10&m》8.5 & &（大于等于我用》表示） & &又因为m为正整数，所以m=9，则A(9,0) &, & B(0,18)过点C作OA的垂直线CD, 则三角形CDA相似于三角形BOA,所以BA:CA=BO:CD；又因为OC是角AOB的平分线，所以 &BC:CA=OB:OA=18:9=2:1 ，那么BA:CA=3:1 &即BO:CD=3:1,CD=18/3=6 &;再过C点作CE平行于OA，则三角形BEC相似于三角形BOA，所以BO:BE=OA:EC &, （我用＃表示平行） 因为EC#OA , BO#CD，所以EO=CD=6 , 那么BE=BO-EO=18-6=12,则OA:EC=BO:BE=18:12=3:2 , OA:EC=9:EC=3:2 , 即EC=6 , 那么C（6，6）第三题算不出来。。。不好意思能力有限log底数是(2+根号3)真数是2-根号3求解答过程,最好有解析!_百度作业帮
log底数是(2+根号3)真数是2-根号3求解答过程,最好有解析!
log底数是(2+根号3)真数是2-根号3求解答过程,最好有解析!
要看2-√3等于2+√3的多少次方∵（2-√3)(2+√3）=4-3=1∴2-√3=1/(2+√3)=(2+√3)^(-1)∴log(底2+√3) (2-√3)=-1
第二步为什么是4-3啊？
平方差公式呀
(a+b)(a-b)=a&#178;-b&#178;
因为（2+√3）（2-√3）=1所以 log（2+√3）（2-√3）=-1
——底数是(2+根号3)真数是2-根号3的对数
我不懂为什么（2+√3）（2-√3）要乘起来？
log&#8249;2+√3&#8250;(2-√3)=log&#8249;2+√3&#+√3)]=log&#8249;2+√3&#8250;1-log&#8249;2+√3&#8250;(2+√3)=0-1=-1求解答过程！？_百度知道
提问者采纳
谢谢，很高兴有帮到忙
提问者评价
太给力了，你的回答完美地解决了我的问题，非常感谢！
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出门在外也不愁求解答过程：阅读理解。_百度知道
求解答过程：阅读理解。
阅读理解。
&&&&&&There was once a captain who loved money so much that he cheated his sailors at the end of every
voyage and took their wages.
&&&&& On the last day of one voyage, the ship was in a small port. It was winter time, and the sea was very cold, so the captain said to his sailors, "If one of you stays in the water during the whole night, I will give
him my ship. But if he comes out before the sun appears, I shall get his wages."
&&&&& The sailors had heard about the captain's cheating, so they didn't trust him. But then one of them, who thought that he was cleverer than the captain, said that he would do it. He got into the water, and, though it was very cold, he stayed in it. When it was nearly morning, some fishermen lit a fire on the shore about half a mile away.
&&&&&& "You are cheating," the captain said to the sailor. "The fire's warming you."
&&&&&& "But it's half a mile away!" said the sailor.
&&&&&& "A fire's fire," answered the captain. "I have won."
&&&&&& The sailor came out of the water, and said, "Perhaps you think that you are clever because you have
won my wages, but you can't cook a chicken."
&&&&&& "I can," answered the captain. &&&&& &"If you cook this chicken," said the sailor, "I shall work for you without wages for seven years, but
if you can't, you will give me your ship."
&&&&&& The captain agreed, took the chicken and said, "Where's the fire?"
&&&&&& "There it is," answered the sailor. "On the shore."& &&&&&&&"But it's half a mile away," said the captain angrily.
&&&&&& " 'A fire's fire,' you said," answered the sailor. "If it is enough to warm me in the water, it is enough
to cook your chicken."
1. The captain got the sailors' wages _____.
A. to buy a chicken for himself B. and kept the money for future use
C. by cheating him D. and said he would return the money soon
2. Which of the following statements is TRUE?
A. All the sailors refused to get into the water because it was too cold.
B. The captain knew that the fire the fishermen made was enough to warm the sailor in the water.
C. The captain succeeded in cheating the sailor.
D. It was the sailor who was cleverer.
3. The captain insisted that the fire was warming the sailor because he _____.
A. didn't want to lose the bet B. didn't believe the sailor's success
C. wanted to keep his promise D. wanted to show his cleverness
4. Which of the following statements is NOT TRUE?
A. The sailors didn't trust the captain. B. In order to help the sailor in the water, the fishermen made a fire. C. The captain failed to cheat the sailor this time. D. The sailor didn't get out of the water before the sun appeared.
5. What is the title of the story?
A. How a Captain Cheated His Sailor
B. How a Sailor Got a Ship
C. A Brave Sailor
D. A Fire Is Fire
我有更好的答案
1-5: CDABD
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出门在外也不愁求解答过程：根据短文内容，完成表_百度知道
求解答过程：根据短文内容，完成表
根据短文内容，完成表格中的内容配对。
&&&& English idioms are interesting. An idiom is a phrase that we can't understand from the meaning of each word. For example, if an American boy asks his mom what's for dinner tomorrow, she may say
"I'll play it by ear", that means she doesn't have plans for dinner and she will decide later. &&&& &"Play it by ear" used to mean playing music without using the music (乐谱), but now people often use it when they're not talking about music!
&&&& There are many idioms in English. If you learn to use them, your English will be much more
vivid (生动的) and colorful.
&&&& Have you ever heard the idiom "He bought the farm?" It means he died. Do you know how it
became popular? It was first used in World War I. When a soldier died, the government gave his
family enough money to buy a farm. &&&& &In the early 1930s, people in the US often did not know when or where their next meal was. So as soon as they got something in their hand that could be eaten, it would go into their mouth. That
was how people began to use the idiom "living hand to mouth" to mean "living a poor life".
&&&& And don't be angry if your English friend says this to you, "Break a leg in your game!" He is
wishing you good luck! Hundreds of years ago, people believed in sprites (小妖精). Sprites enjoyed
causing trouble. If the sprites heard you ask for something, they would make the opposite happen. Tell someone to "break a leg" and the sprites would make something good happen.
&&&& Aren't English idioms interesting? And break a leg in your next football match!
Original (原始的) meaning
Current (现时的) meaning
1. play it by ear
A. bad thing&
a. He died
2. He bought the farm?
B. going into their mouth as soon as they
&&& got something in their hand
b. not have plans for dinner&
3. living hand to mouth&
C. play music without using the sheet music
c. Wish you good luck!
4. Break a leg in your game!
D. When a soldier died, the government gave
&&&& his family enough money to buy a farm.
d. living a poor life
1. ______ ______&&&&& 2.______ ______& && 3._____ _____&&&& &4._____ _____
我有更好的答案
1. C,b&& 2. D,a&& 3. B,d&& 4. A,c
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出门在外也不愁}