1. Is the function y = f (x) increasing or decreasing on a monotone interval Question 1 y = X-5 X-6 The second question is y = 9-x square 2. Prove that the function y (x) = x + 1 is a decreasing function on (negative infinity, 0) The function y (x) = 1-1 / X is an increasing function on (negative infinity, 0)

It is proved that the increasing and decreasing function can be proved by taking X1 and X2 and carrying them into the original formula respectively to simplify the difference and judge the size of the final result
The second problem is just an interval problem. The method is the same as 1

1. Let m = {1,3, X}, n = {x ^ 2-x + 1}. If M ∪ n = m, then the value of X is ()
2. Known mapping: a → B, where a = b = R. the corresponding rule is f: y = - x ^ 2 + 2x. For real number k ∈ B. there is no corresponding element in a, then the value range of K is ()
3. If f (x) satisfies f (x) = f (4-x) and - 2 ≤ x < 0, f (x) = x (1-x)?

Let m = {1,3, X}, n = {x ^ 2-x + 1}. If M ∪ n = m, then the value of X is () m ∪ n = m; X ^ 2-x + 1 = 1 or 3 or X; X ^ 2-x + 1 = 1; X = 0; x ^ 2-x + 1 = 3; X = 2 or - 1; X ^ 2-x + 1 = x; no solution; so: x = 0,2, - 1; 2. Known mapping: a → B, where a = b = R. the corresponding rule is f: y = - x ^ 2 + 2x

Please comment on Du Fu's article with 300-400 words. Don't give a brief introduction to Du Fu

Guo Moruo:
The poet said that the thatch on the roof of the hut he lived in has three layers. This means that the roof of the old house has been covered twice. Generally speaking, one layer is about four or five inches thick, and three layers are more than a foot thick. Such a hut is warm in winter and cool in summer. Sometimes it is more exquisite than living in a tile roofed house. Part of the thatch is blown away by the strong wind, The poet is complaining and hating people. It's amazing that he calls the poor children thieves. How much can the children pick up when they pick up the grass blown away by the wind? Thanks to the poet's loud stop, he shouts "his lips are burning and his mouth is dry". The poor children are called thieves, but his son is jiao'er. He is talking about his poverty, However, he forgot that the peasants were 100 times poorer than him. The fantastic dream of "thousands of houses" was equally praised by the old and new research experts, who thought that "there is a great sense of the people and things", or "this is enough to represent the general voice of the people". In fact, what the poem said was clearly "poor scholars", which was meant to serve the scholars who have not been well-off or who have been well-off but not well-off, How can it be expanded into "people" or "people"? The children of the peasants have taken some thatched grass which has been blown away by the wind, and they are all called thieves. Do the peasants still hope to live in Guangxia? There must be tens of millions of such "Guangxia". I don't know how much labor it will cost. I'm afraid the poet doesn't dream of it. Generosity is very generous, as long as the poor people all over the world like it, It doesn't matter if he lives in a dilapidated house and freezes to death. But if so many Guangxia really sprang up like mushrooms overnight, wouldn't the poet have lived in it long ago? The so-called Great Harmony of "people and compatriots, things for us" and "people are hungry, people are hungry, people drown themselves" are just the subjective imagination of some scholar bureaucrats

At 7:40, Xiao Ming walks to his grandmother's house, which is 6 kilometers away. His walking speed is 3 kilometers per hour, but he has to rest for 10 minutes every 40 minutes, so he can't walk______ The time has come

It takes 2 hours and 20 minutes for Xiao Ming to go out at 7:40, then he will have a rest at 7:40 + 2 hours and 20 minutes = 10 hours

Who has taught the translation of section B 3a in unit 10 of grade 9 English edition, thank you!

In 1938, a radio program broadcast by actor Orson wells announced that aliens from Mars had landed on the earth. He described where aliens landed and told the audience how aliens moved to every corner of the United States. Wells was so convincing that hundreds of people believed it

How to find the greatest common factor of 26 and 65
There is also short division

When - 3 ≤ x ≤ 1, the corresponding value of Y is 1 ≤ y ≤ 9, then the value of KB is 1______ ．

From the properties of the first-order function, when k > 0, y increases with the increase of X, so − 3K + B = 1K + B = 9, the solution is k = 2, B = 7, that is, KB = 14; when k < 0, y decreases with the increase of X, so − 3K + B = 9K + B = 1, the solution is k = - 2, B = 3, that is, KB = - 6, so the value of KB is 14 or - 6

Try to answer the rational number in the first day of junior high school. Thank you
4. The following comparison results are correct ()
A．-3|-a| C．a≥-|-a| D．a

4. The following comparison results are correct
A．-3|-a| C．a≥-|-a| D．a

There are 300 chickens and ducks in Uncle Wang's family. There are 40 more chickens than ducks. How many chickens and ducks are there?

（300-40）÷2=130
130+40=170
There are 170 chickens and 130 ducks
Pro, please click "evaluation" in the upper right corner and choose "satisfied". Thank you!

Given the range of function f (x) [0,4] (x ∈ [- 2,2]), function g (x) = AX-1, X ∈ [- 2,2], ∀ x1 ∈ [- 2,2], total ∃ x0 ∈ [- 2,2], such that G (x0) = f (x1) holds, then the value range of real number a is______ ．

According to the meaning of the question, we can get: ① when a > 0, − 2A − 1 ≤ 02A − 1 ≥ 4, we get a ≥ 52; ② when a < 0, − 2A − 1 ≥ 42a − 1 ≤ 0, we get a ≤ - 52; ③ when a = 0, G (x) = AX-1 = - 1, ∪ - 52] ∪ [52, + ∞]. So the answer is [- ∞, - 52] ∪ [52, + ∞]