Math Expert: Hurry up, okay! Math Wizards, Come In!

It's so simple, because it's supposed to be a semester of high school, I won't do it. Go home and forget it, the first one, set the point c(x,3x) to write the coordinates of the vector ab and cd, and according to the perpendicular to the two vectors, x1x2 + y1y2 = 0, you can calculate x.

The second one draws a diagram to see that the oblique triangle is still a special angle.

Question 3 f(x)=cosx+3sinx 2sinx+cosxThe second question, the numerator and denominator are divided by cosx.

Fourth, cos(x-y) = cosxcosy + sinxsiny is equal to the root number of 5 by adding the square of the following condition cosx-cosy plus the square of sinx-sinySimplification can get the answer, the second question, first find siny. According to the first question, sinx can be calculated, and the above alpha beta is represented by x,y.

I'm just saying an idea, and I'm still supporting a few of the people upstairs.

I will, 20 will not be too little, I'll give you a question first, there's not much time.

17 questions |a+b|2=a 2+b 2+2abcos303+4+2x root number 3x2xcos30

7 + 4 times the root number 3 x half of the root number 3

So |a+b|= 42 under the root number

Note: There are arrows on A and B, and there are no cos in front of them.

The same can be obtained |a-b|=1

The question of the second year of high school, if you don't ask it here, I won't give you an answer.

I won't answer with you, that's it, it's not good to count yourself, one word "lazy".

Such a simple high school topic. You're too,

Support the first two buddies.

Work hard, kid.

Categories: Annoyances >> campus life.

Problem description: I am a student in Yinchuan! High 2! Oh! Lose your marbles! That math is abominable! I only got a 68 out of 150! Shame on you! I just think math is so hard to learn! Teach me well?

Can anyone teach me!!

Analysis: Hello! I was a junior in high school, but I didn't study in my third year of high school due to my family's financial difficulties, so I went to work for work.

It stands to reason that I should be called your senior sister, because you were still in your first year of high school when I was a sophomore in high school. It's a pity that the book doesn't say much, and it can't help you solve any problems, so I can only tell you some learning methods.

First of all, you can't be afraid of mathematics, don't think about it too hard, in fact, sometimes some problems are easy, but you always listen to others say how difficult it is, and you give up without thinking about it, this is the psychological effect. You have to know that everyone's brain is different and they all have different ideas. It's the same with questions, maybe what they think won't work, but what you think will work!

I remember that I did well in math in my first and second years of high school, but I was one of the best in my class, so I want to emphasize that I was still a girl! For a girl, math learning is really good! At that time, my classmates always asked me if I had any study skills, but I didn't have any skills, I mainly did more practice questions than others, and I also asked more questions to the teacher.

Here I want to remind you that you can't learn to be a little false: as long as there are questions you don't understand, you have to ask, you must not pretend to understand, so that your academic performance is difficult to improve, only when you encounter a problem you have to solve, so that you don't understand the problem less and less, the more you learn, the more your academic performance will come up.

There is also math can not be rote memorization, so that you do not remember it firmly, this is a mistake that many students are prone to make, always remember well when learning, but when it comes to use, it always seems to understand non-understanding, and rote memorization will make math boring, and it is boring to learn. So to understand the memory, to understand the memory on the basis of the memory, the effect will be much better. If you want to learn a course well, you must first be interested in it, so that you will be more motivated to learn.

The most important thing is to persevere, and not to waste halfway, then all the work will be wasted. Don't be afraid of hardship.

That's all I'm going to say, maybe you've heard these words in the teacher**, but I guess you definitely didn't take it seriously! I hope you don't take what I'm saying here seriously, you don't think about anything else, just think about what I've said so much, and I've wasted a lot of time typing. I hope you have pity on my typing hands!

Take a good look at it, and I hope your math scores will improve soon.

Oh, and don't forget to give me extra points!

-92 Third: (-8-2) 2=-20

Fourth: (-20-2) 2=-44

Fifth: (-44-2) 2=-92

1) When be ce=1, cf= 6 cm, abe cef2) when be ce=2, find the value of sin dab;

i.e. be=4ab=6

ae=2√13

sin bae = 4 2 13 = 2 13 lead nano 13cos bae = 6 2 13 = 3 13 13 sin bab = 2 sin baecos bae = 12 13cos bab = 5 13

sin∠dab′=sin(90°-∠bab′)=cos∠bab′ =5/13

3) When be CE= X (point C does not coincide with point E), please write the relationship between the bridge surge area Y and X of the common part of the ABCD after ABE is folded.

ce=6-be

ce=be/x

6-be=be/x

6x-xbe=be

be=6x/(1+x)

s△abe=1/

1/2×6×be

3 6x Min J (1+x).

18x/(1+x)

y=18x/(1+x)

Bottom circumference:

Base radius: A base area is a square centimeter.

The two base areas are square centimeters.

This should be thought of by yourself, after all, the workbook is to train your ability, if you use the answer copy, what is the point?

Good luck.

Set A and set B are subtracted to get one chicken is yuan.

Set B and Set C are subtracted to get a burger.

Then subtract a burger and a chicken from set C to get a salad that takes 10 meters a second.

A-B gets chicken ** yuan.

b-c has to be a hamburger** dollar.

Substitute c to get salad ** yuan.

Column ternary system of equations, solved.

B set minus C set to get burger dollars.

A set minus C set to get chicken + hamburger 8 yuan, and hamburger yuan is chicken yuan.

then salad dollars.

A set - B set = egg price = yuan.

Set B - Set C = Burger Price = Yuan.

Salad price = yuan.

Answers: 1, (1) 4;

2、（1）n-3；

2）n-2；

3）1/2 n（n-3）；

I'm glad to solve the above problems for you, I hope it will help you in your studies! 】≤