There are 5 key phrases and 15 sentences in unit 11 of PEP English eighth grade volume 1

There are 5 key phrases and 15 sentences in unit 11 of PEP English eighth grade volume 1

Could you please Can you Do you want to do it 2. Do the dishes 3. Sweep the floor 4. Take out the trash 5. Make one's bed 6. Fold one's clothes 7. C

Unit 6 phrases, key sentences
People's education press new target eighth grade volume I as long as unit 6 is enough, ten phrases, ten sentences

(1) (2) more popular (3) photos of me (4) as you can see (5) in some ways (6) look the same / look different

Urgent need! Please help! Grade 8 English volume 1 text page 34!

A: I think a good friend makes me laugh. B: for me, a good friend likes to do the same thing as me. C: Yes, a good friend is very popular. D: it's not very important. I don't have an article on page 34 of English volume 1 of Grade 8. It's section B 1B on page 34 of people's education press

It is known that the quadratic function f (x) satisfies the following conditions: F (0) = f (1) = 1 and the inequality f (x) ≥ x is r constant for X. The expression of function f (x) is obtained
It is known that the quadratic function f (x) satisfies the following conditions: F (0) = f (1) = 1 and the inequality f (x) ≥ x is r constant for X. The expression of function f (x) is obtained

Let f (x) = ax & # 178; + BX + C
From F (0) = 1
That is, f (0) = A0 & # 178; + b * 0 + C = 1, that is, C = 1
That is, f (x) = ax & # 178; + BX + 1
And f (1) = 1
That is, a * 1 & # 178; + b * 1 + 1 = 1
That is, a + B = 0
That is, B = - A
That is, f (x) = ax & # 178; - ax + 1
It is also true that f (x) ≥ x belongs to R constant for X
That is, ax & # 178; - ax + 1 ≥ x is r constant for X
That is, ax & # 178; - ax-x + 1 ≥ 0 is r constant for X
That is, ax & # 178; - (a + 1) x + 1 ≥ 0 is r constant for X
That is, a > 0 and Δ ≤ 0
That is, a > 0 and Δ = [- (a + 1)] ² - 4A ≤ 0
That is, a > 0 and Δ = A & # 178; + 2A + 1-4a ≤ 0
That is, a > 0 and Δ = A & # 178; - 2A + 1 ≤ 0
That is, a > 0 and Δ = (A-1) &# 178; ≤ 0
That is, a = 1
That is, f (x) = x & # 178; - x + 1

Given that 13 ≤ a ≤ 1, if f (x) = ax2-2x + 1 in the interval [1,3], the maximum value is m (a), and the minimum value is n (a), let g (a) = m (a) - n (a), find the functional expression of G (a)

The symmetry axis of F (x) = ax2-2x + 1 is x = 1a, ∵ 13 ≤ a ≤ 1, ∵ 1 ≤ 1a ≤ 3, ∵ f (x) on [1,3], n (a) = f (1a) = 1-1a. ∵ f (x) = ax2-2x + 1 on interval [1,3], the maximum value is m (a), and the minimum value is n (a), ∵ ① when 1 ≤ 1a ≤ 2, i.e. 12 ≤ a ≤ 1, m (a) = f (3) = 9a-5, n (a) = f (1a) = 1-1a. G (a) = m (a) - n (a) = 9A + 1a-6 When 2 ≤ 1a ≤ 3, i.e. 13 ≤ a < 12, m (a) = f (1) = A-1, n (a) = f (1a) = 1-1a. G (a) = m (a) - n (a) = a + 1a-2. G (a) = 9A + 1A − 6, 12 ≤ a ≤ 1A + 1a − 2, 13 ≤ a < 12

Problem solving, with one variable equation, detailed process, please
A. B is 20 kilometers away from each other. Party A and Party B travel from a and B at the same time. Two hours later, they meet on the way. Then Party A returns to place a, and Party B goes on. When Party A returns to place a, Party B is 2000 meters away from place a!

Let a's velocity be x and B's velocity be (2x-2) / 2 = X-1
2（X-1+X）=20
2X-1=10
X=5.5
A's speed is 5.5 km / h
B's speed is 4.5 km / h

Finding the tangent slope of a curve through a fixed point by derivative
(3 + 1 x ^ 2 y ^ 2) &; 2 xy = &; 5.76, calculate the tangent slope of the curve at (6,1). Please describe the process and answer in detail. Is it right to directly calculate the derivative y '? But the answer is wrong. In addition, this point is not exactly on the curve. Ah, if it can't be done again, it seems that I miscalculated or what, ask for guidance!

In this paper, we first deal with the following equation: 3 + X & # 178; Y & # 178; = (2xy-5.76) &# 178; = 4x & # 178; Y & # 178; - 23.04xy + 33.17763x & # 178; Y & # 178; - 23.04xy + 30.1776 = 0, where y is regarded as y (x), and the compound derivation rule 3 * (2XY & # 178; + 2x & # 178; y * y ') - 23.04 (y + XY') = 0 is used to solve the equation

It is known that a, B and C are in equal proportion sequence, X is the mean of a and B, and Y is the mean of B and C. It is proved that a / x + C / y = 2

Certification:
a. If B and C are equal ratio sequence, then B ^ 2 = AC
X is the median of a and B, x = (a + b) / 2
Y is the median term of B and C, y = (B + C) / 2
therefore
a/x+c/y
=2a/(a+b)+2c/(b+c)
=2(ab+bc+2ac)/(ab+bc+ac+b^2)
=2(ab+bc+2ac)/(ab+bc+2ac)
=2
I'm glad to answer for you. If you are satisfied, please click the top right corner and choose it as the satisfied answer,

How to deduce the formula of clock slowness and scale contraction effect in relativity?

Under the premise of constant speed of light, it is the inevitable result of Lorentz transformation of inertial system. Read the reference link. This page has the formula derivation process——

2x-1/6-3x+1/8=x/2-1
6 and 8 are the denominators, and the last one is also the denominator. The others are numerators,

2x-1/6-3x+1/8=x/2-1
4(2x-1)-3(3x+1)=12x-24;
8x-4-9x-3=12x-24;
13x=17;
x=17/13