K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

6 tháng 9 2018

20 tháng 12 2023

(C): \(y=x^3-3x^2+1\)

=>\(y'=3x^2-3\cdot2x=3x^2-6x\)

Tiếp tuyến của (C) tại điểm có x=3 có dạng là:

\(y-y\left(3\right)=f'\left(3\right)\cdot\left(x-3\right)\)

=>\(y-\left(3^3-3\cdot3^2+1\right)=\left(3\cdot3^2-6\cdot3\right)\left(x-3\right)\)

=>\(y-1=9\left(x-3\right)=9x-27\)

=>y=9x-27+1=9x-26

Gọi A(x,y) và B(x,y) lần lượt là tọa độ giao điểm của đường thẳng y=9x-26 với trục Ox và trục Oy

Tọa độ A là:

\(\left\{{}\begin{matrix}y=0\\9x-26=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{26}{9}\\y=0\end{matrix}\right.\)

Tọa độ B là; \(\left\{{}\begin{matrix}x=0\\y=9\cdot0-26=-26\end{matrix}\right.\)

Vậy: A(26/9;0); B(0;-26)

\(OA=\sqrt{\left(\dfrac{26}{9}-0\right)^2+\left(0-0\right)^2}=\dfrac{26}{9}\)

\(OB=\sqrt{\left(0-0\right)^2+\left(-26-0\right)^2}=26\)

Vì Ox\(\perp\)Oy nên OA\(\perp\)OB

=>ΔOAB vuông tại O

=>\(S_{OAB}=\dfrac{1}{2}\cdot26\cdot\dfrac{26}{9}=\dfrac{338}{9}\)

=>Chọn D

29 tháng 10 2021

Bài 1:

a: UCLN(180;234)=18

UC(180;234)={1;2;3;6;9;18}

b: UCLN(60;80;176)=4

UC(60;80;176)={1;2;4}

18 tháng 1 2017

 The area of a parallelogram is: 156 x 210= 32760 m2

 The area of a parallelogram is: 19 x 17= 323 m2

28 tháng 8 2021

1. I would help him if he (ask) …asked………………me.
2. What would you do if you (see) ……saw……………a snake?
3. What would he do if he (have) …had………………a lot of money?
4. John would win more races if he (train) ……trained……………harder.
5. How would your father react if you (leave) ……left……………school?
6. I would gladly tell you the answer if I (know) ………knew…………myself.
7. I would be a millionaire if I (win) ………won…………the first lottery prize.
8. That student could get much higher marks if he (study) ………studied…………harder.
9. The world would be a better place if there (be) ………were…………fewer road accidents.
10. Mr. Nam would be very happy to meet his old friends if they (come) ………came…………to see him.

* Give the correct form of the verb in bracket.1. I would help him if he (ask) ……………………me.2. What would you do if you (see) ……………………a snake?3. What would he do if he (have) ……………………a lot of money?4. John would win more races if he (train) ……………………harder.5. How would your father react if you (leave) ……………………school?6. I would gladly tell you the answer if I (know) ……………………myself.7. I would be a millionaire if I (win) ……………………the first lottery prize.8. That student could get much higher marks if...
Đọc tiếp

* Give the correct form of the verb in bracket.
1. I would help him if he (ask) ……………………me.
2. What would you do if you (see) ……………………a snake?
3. What would he do if he (have) ……………………a lot of money?
4. John would win more races if he (train) ……………………harder.
5. How would your father react if you (leave) ……………………school?
6. I would gladly tell you the answer if I (know) ……………………myself.
7. I would be a millionaire if I (win) ……………………the first lottery prize.
8. That student could get much higher marks if he (study) ……………………harder.
9. The world would be a better place if there (be) ……………………fewer road accidents.
10. Mr. Nam would be very happy to meet his old friends if they (come) ……………………to see him.

1
10 tháng 2 2022

1, asked

2, saw

3, had

4, trained

5, left

6, knew

7, won

8, studied 

9, were

10, came

10 tháng 2 2022

cảm ơn ạ

11 tháng 5 2018

1. will-help

2. doesn't-won't help

3. will-do-doesn't help

Tick cho mik nha

12 tháng 5 2018

1. She (help) ..will help.. if I (help) ..help.. her

2. If she (not help) ..doesn't help.. me I (not help) ..won't help.. her

3. What ..will.. you ..do.. if she (not help) ..doesn't help.. you?