八年级上册数学题50道 八年级下册数学19.3第1.2.3题急

八年级下册数学19.3第1.2.3题急  

八年级下册数学19.3第1.2.3题急

1、SinA=20/29，CosA=21/29，tanA=20/21，cotA=21/20，SinB=21/29，cosB=20/29，tanB=21/20，cotB=20/21. 2、sinA=3/5，cotA=4/5，tanA=3/4，cotA=4/3(提示：可设BC=3k，AC=4k，侧根据勾股定理，AB=5k) 3、(1)0 (2)1 希望可以采纳、谢谢。已经有不懂的，可以找我、谢谢。

把中文翻译成英文、、、急~~~~~！

Many students may have the same worry like yours.Certainly,it's wrong of your parents to read your own diaries and messages but you don't know.We can understand that parents want to know what their child thinks about at all times,but they must look for a great way to understand us.As a child ,we should face the parents' mistakes,because blame too much doen't help.I believe that you are clever enough to treat your parents correctly.We should also consider them as a friend and talk with them as much as possible.Maybe we can talk about the school life and the classmates with them to make us closer.

急！急！急！脑筋急转弯高手请进来

流星雨
一拍即合
坐的是汽车上的椅子
恶果
上当
身体坏了的人

急!!!!大侠们救救我的硬盘..

先不要低格，逐个盘格式化，装重操作系统。如果还不行，就考虑用dos工具，屏蔽坏道(软屏蔽)。如果再不行，再考虑低格。

请问这道题怎样算，急，谢谢

分四种情况讨论：
（1）把被减数个位上的2看成了5,减数十位上的7看成4,则有
（5-2）-（4-7）＊10=33
正确的差是错误的差加33
（2）把被减数个位上的2看成了5,被减数十位上的7看成4,则有
（5-2）+（4-7）＊10=-27
正确的差是错误的差减27
（3）把减数个位上的2看成了5,减数十位上的7看成4,则有
-（5-2）-（4-7）＊10=27
正确的差是错误的差加27
（4）把减数个位上的2看成了5,被减数十位上的7看成4,则有
（4-7）＊10-（5-2）=-33
正确的差是错误的差减33

(-1/7)+(-2/35)-(-2/5）求过程，急

将-1/7上下同时乘以5得到-5/35 -2/5同乘以7得到-14/35 最后答案为-21/35

求一篇初一英语作文 急

你好，很高兴为你解答。

保证正确率~！

【作文】：

Dear Tony ,

I am very glad to write to you.  Then I would like to tell you several rules at my school as follows:

First , we mustn't  be late. Second, we shall never run in the corridor. Third , we should listen carefully to the teachers in class. Forth, we are not allowed to eat food during the class. Finally, we should go home after class.

Yours sincerely

Dale

不懂请追问，(*^__^*) 嘻嘻~~

望采纳，祝开心~！

急！需帮忙！急须一份KTV的宣传单

这种要付费的。免费的谁会帮你做啊？

这是柯南的哪一集？？？？急！求帮助

是44集江户川柯南诱拐事件，片尾曲过后，我刚看完呢~

咋做急十万火急求大神帮忙啊

由图可以看出A中花了10秒，B中花了18-10=8秒（液面升高的速度不同）