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18 tháng 1

Olm chào em. Cảm ơn em đã dùng nền tảng olm cho việc học tập và giao lưu với cộng đồng tri thức. Đây không phải là toán lớp 4. Vì vậy em cần đăng đúng môn học.

em bị nhầm ạ

NV
24 tháng 9 2020

ĐKXĐ: ...

a/ \(cotx=\frac{2}{3}\Leftrightarrow x=arccot\left(\frac{2}{3}\right)+k\pi\)

b/ \(tanx=-\frac{4}{3}\Leftrightarrow x=arctan\left(-\frac{4}{3}\right)+k\pi\)

c/ \(sinx=\frac{1}{2}\Leftrightarrow\left[{}\begin{matrix}x=\frac{\pi}{6}+k2\pi\\x=\frac{5\pi}{6}+k2\pi\end{matrix}\right.\)

d/ \(cotx=-\frac{1}{2}\Leftrightarrow x=arccot\left(-\frac{1}{2}\right)+k\pi\)

e/ \(cotx=1\Leftrightarrow x=\frac{\pi}{4}+k\pi\)

f/ \(sin\left(x+\frac{\pi}{2}\right)=1\Leftrightarrow x+\frac{\pi}{2}=\frac{\pi}{2}+k2\pi\Leftrightarrow x=k2\pi\)

g/ \(3x=k\pi\Leftrightarrow x=\frac{k\pi}{3}\)

I/ Choose the best answer: 1. Choose the word which is pronounced differently from the others: A. wanted B. worked C. needed D.visited 2. Choose the word which has different stress from the others: A. lacquerware B. pottery C. embroider D.layer 3. He works as an ___________ in his uncle’s workshop. A. attraction B. artisan C....
Đọc tiếp

I/ Choose the best answer:

1. Choose the word which is pronounced differently from the others:

A. wanted

B. worked

C. needed

D.visited

2. Choose the word which has different stress from the others:

A. lacquerware

B. pottery

C. embroider

D.layer

3. He works as an ___________ in his uncle’s workshop.

A. attraction

B. artisan

C. embroider

D.lacquer

4. They need to find a solution to ___________ the local environment.

A. preserve

B. cast

C. weave

D.knit

5. The company is going to close ___________ one of its stores due to reduced sales.

A. on

B. down

C. in

D.at

6. He was hired for the position because he is ___________.

A. reliability

B. reliably

C. reliable

D.unreliable

7. I love going to this place _____________ it’s the quietest place in the city.

A. so

B. though

C. so that

D.as

8. Nothing is __________ than being stuck in a traffic jam.

A. worse

B. badly

C. more badly

D.the worst

9. When I __________, the town hall was already full of teenagers.

A. turned on

B. turned off

C. turned up

D.turned into

10. Nam: There’s a lantern festival nearby. Do you want to come with us?

Mai: Yeah, ___________ !

A. sorry

B. cool

C. I see

D.not at all

11. Remember to _________ your shoes when you enter a Japanese house.

A. take over

B. take on

C. take up

D.take off

12. The roads are ___________ as one of the solutions to deal with traffic jams.

A. extended

B. expensive

C. overcrowding

D.shelter

1
24 tháng 3 2020

I/ Choose the best answer:

1. Choose the word which is pronounced differently from the others:

A. wanted

B. worked

C. needed

D.visited

2. Choose the word which has different stress from the others:

A. lacquerware

B. pottery

C. embroider

D.layer

3. He works as an ___________ in his uncle’s workshop.

A. attraction

B. artisan

C. embroider

D.lacquer

4. They need to find a solution to ___________ the local environment.

A. preserve

B. cast

C. weave

D.knit

5. The company is going to close ___________ one of its stores due to reduced sales.

A. on

B. down

C. in

D.at

6. He was hired for the position because he is ___________.

A. reliability

B. reliably

C. reliable

D.unreliable

7. I love going to this place _____________ it’s the quietest place in the city.

A. so

B. though

C. so that

D.as

8. Nothing is __________ than being stuck in a traffic jam.

A. worse

B. badly

C. more badly

D.the worst

9. When I __________, the town hall was already full of teenagers.

A. turned on

B. turned off

C. turned up

D.turned into

10. Nam: There’s a lantern festival nearby. Do you want to come with us?

Mai: Yeah, ___________ !

A. sorry

B. cool

C. I see

D.not at all

11. Remember to _________ your shoes when you enter a Japanese house.

A. take over

B. take on

C. take up

D.take off

12. The roads are ___________ as one of the solutions to deal with traffic jams.

A. extended

B. expensive

C. overcrowding

D.shelter

I/ Choose the letter (A, B, C or D) that indicates the best answer to each of the following questions. Write your answers in the box provided. 1. Choose the word which is pronounced differently from the others: A. proofs B. books C. points D.days 2. Choose the word which has a different stress from the others: A. pollute B. deny C. happen D. occur 3. Choose the word which is...
Đọc tiếp

I/ Choose the letter (A, B, C or D) that indicates the best answer to each of the following questions. Write your answers in the box provided.

1. Choose the word which is pronounced differently from the others:

A. proofs

B. books

C. points

D.days

2. Choose the word which has a different stress from the others:

A. pollute

B. deny

C. happen

D. occur

3. Choose the word which is pronounced differently from the others:

A. meal

B. tea

C. meat

D.bread

4. Mary often goes to the supermarket ____________ Sundays.

A. in

B. at

C. from

D.on

5. _________ it was so cold, he went out without an overcoat.

A. Although

B. Because

C. As

D.If

6. Tom said that he _________in Leeds in England.

A. is living

B. lived

C. were living

D.has lived

7. ___________ does it take you to your hometown? – About 30 minutes.

A. How often

B. How far

C. How long

D.How many

8. Lan ________the train if she is not in a hurry.

A. will miss

B. misses

C. missed

D.will not miss

9. His salary isn’t enough for his family to live _____________.

A. at

B. about

C. on

D.into

10. Karachi in Pakistan is the second __________ city in the world in population.

A. large

B. larger

C. more large

D.largest

11. When he was young, he ___________go fishing with his father.

A. used

B. uses

C. used to

D.is using

12. Mai: “Thank you very much for helping me!” – Nam: “ _____________.”

A. Not at all

B. Good idea

C. Sorry

D.Cool

13. She helped me to ____________ my son while I was away.

A. take over

B. look after

C. look at

D.get off

14. The traffic is so heavy. I wish there ________ fewer cars.

A. are

B. were

C. will be

D.have been

15. The children felt __________when their mother was coming back home.

A. excitement

B. excitedly

C. excited

D.exciting

1
31 tháng 3 2020

I.

1D. days

2C. happen

3D. bread

4D. on

5A. although

6D. has lived

7C. how long

8A. will miss

9C. on

10D. largest

11C. used to

12A. Not at all

13B. look after

14B. were

15C. Excited

12 tháng 5 2023

Bạn bổ sung đề đầy đủ nhé

11 tháng 2 2020
https://i.imgur.com/cPS0DnH.jpg
#include<bits/stdc++.h>using namespace std;int main() {  int n;  cin>>n;  int A[n],B[n],C[2*n];  for (int i=0; i<n;i++)    {    cin>>A[i];  }  for (int i=0;i<n; i++)  {    cin>>B[i];  }  for (int i=0;i<n;i++)   {    C[2*i]=A[i];    C[2*i+1]=B[i];  }  for (int i=0; i<2*n;i++)   {    cout<<C[i]<< " ";  }}   #include <iostream>using namespace std;int main(){    int n, x;    cin >> n;    int a[n];    for (int i = 0; i < n; i++)        cin >> a[i];    int q;    cin >> q;    while (q--)    {        int cnt...
Đọc tiếp

#include<bits/stdc++.h>
using namespace std;
int main()
 {
  int n;
  cin>>n;
  int A[n],B[n],C[2*n];
  for (int i=0; i<n;i++)
    {
    cin>>A[i];
  }
  for (int i=0;i<n; i++)
  {
    cin>>B[i];
  }
  for (int i=0;i<n;i++)
   {
    C[2*i]=A[i];
    C[2*i+1]=B[i];
  }
  for (int i=0; i<2*n;i++)
   {
    cout<<C[i]<< " ";
  }
}

 

 

 

#include <iostream>
using namespace std;

int main()
{
    int n, x;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; i++)
        cin >> a[i];
    int q;
    cin >> q;
    while (q--)
    {
        int cnt = 0;
        cin >> x;
        for (int i = 0; i < n; i++)
            if (a[i] == x)
                cnt++;
        cout << cnt << endl;
    }
    return 0;
}

 

 

#include <bits/stdc++.h>
using namespace std;
long long n, a[100000], i, b[100000], s, j, k;
int main()
{
    cin >> n;
    for (i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    k = 2;
    b[1] = 0;
    for (i = 2; i <= n; i++)
    {
        for (j = 1; j <= i - 1; j++)
        {
            if (a[j] > a[i])
            {
                s++;
            }
        }
        b[k] = s;
        k++;
        s = 0;
    }
    for (i = 1; i <= k - 1; i++)
    {
        cout << b[i] << " ";
    }
}

 

 

0

a, x(x+3)=0

=>x hoặc x+3=0

=>x+3=0

=>x=0-3

=>x=-3

=>x= 0 hoặc x=-3

b, (x-2)(5-x)=0

=>x-2 hoặc 5-x=0

=>x= 0+2 hoặc x= 5-0

=>x= 2 hoặc x= 5

c, (x-1)(x2+1)=0

=>x-1 hoặc x2-1=0

=>x=1   ->(1)

x2-1=0

=>x2=1

=>x=1

Vậy x=1

3 tháng 8 2016

a) x(x+3)=0

=>x=0 hoặc x+3=0

                    x=-3

Vậy x=0; x=-3

b)(x-2)(5-x)=0

=>x-2=0 hoặc 5-x=0

    x=2              x=5

Vậy x=2; x=5

c)(x-1)(x2+1)=0

=>x-1=0 hoặc x2+1=0

    x=1              x2=-1(vô lí)

Vậy x=1