39 phút trước

1 Hình như thiếu đề

2. $f\left(x\right)=\left[{}\begin{matrix}2x\left(x^3-3x\right),x\in\left[-\sqrt{3};0\right]\cup[\sqrt{3};+vc)\\2x\left(3x-x^3\right);x\in\left(-vc,-\sqrt{3}\right)\cup\left(0;\sqrt{3}\right)\end{matrix}\right.$

$f'\left(x\right)=\left[{}\begin{matrix}8x^3-12x\\12x-8x^3\end{matrix}\right.$

Xét $f'\left(x\right)=0$$\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{\pm\sqrt{6}}{2}\\x=0\end{matrix}\right.$

Mk làm theo kiểu gộp cả hai biểu thức của f(x) vào chung BBT

4 cực trị

(Cách xét dấu: trong khoảng $\left[-\sqrt{3};0\right]\cup[\sqrt{3};+vc)$ xét $f'\left(x\right)=8x^3-12x$ với nghiệm $x=-\dfrac{\sqrt{6}}{2};x=0$

trong khoảng $\left(-vc,-\sqrt{3}\right)\cup\left(0;\sqrt{3}\right)$xét $f'\left(x\right)=12x-8x^3$ với nghiệm $x=\dfrac{\sqrt{6}}{2}$

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1 giờ trước (0:48)

a. 125.27

=53.33

=(5.3)3

b. 243.32

= 35.25

=(3.2)5

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2 giờ trước (23:54)

1. These gifts were handed to the customers by the shop manager

The customers were handed these gifts by the shop manager

2. The first prize was awarded to the outstanding employee by the board of directors

The outstanding employee were awarded the first prize by the board of directors

3. Has the Christmas cards been sent to her family?

Has her family been sent the Christmas cards?

4. Anna was given some Apples and some rose flowers

Some Apples and some rose flowers were given to Anna

5. The fridge was moved to the second floor by my father

(câu này chỉ chuyển đc 1 cách vì ko có tân ngữ chỉ người)

6. Some cups of coffee was bought to the visitors in the kitchen

The visitors were bought some cups of coffee in the kitchen

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3 giờ trước (23:22)

because he is tired, he can't work longer

the flight had to be delayed because of the weather was bad

because it was late we dicided to take a taxi home

we couldn't reach the house because the road was flooded

because of her illness, he had to cancel the appointment

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