A = x^2 - 4x + y^2 - y + 5
A=(x^2 - 4x + 4) + (y^2 - y + 1/4) + 5 - 4 - 1/4

A= (x - 2)^2 + (y - 1/2)^2 + 3/4

vì (x - 2)^2 \(\ge\) 0; (y - 1/2)^2 \(\ge\) 0 (1)

nên (x - 2)^2 + (y - 1/2)^2 + 3/4 \(\ge\) 3/4 (2)

từ (1) và (2) => GTNN của biểu thức A là 3/4 khi x = 2; y = 1/2

\(A=x^2-4x+y^2-y+5\)

\(=x^2-4x+4+y^2-y+\frac14+\frac34\)

\(=\left(x-2\right)^2+\left(y-\frac12\right)^2+\frac34\ge\frac34\forall x,y\)

Dấu '=' xảy ra khi \(\begin{cases}x-2=0\\ y-\frac12=0\end{cases}\Rightarrow\begin{cases}x=2\\ y=\frac12\end{cases}\)

CHÁO BẠN

Dạ anh ơi, anh viết sai chính tả ạ!

North

corret

1. painting

2. doing

3. reading

4. play

5. go

1.painting

2.doing

3.reading

4.play

5. go

1C. taking
2 C. reading
3 C. to play

1.C

2.c

3.B

my father is an engineer.he works for the company

is;works

- \(\frac{x^3}{8}\) + \(\frac34x^2\) - \(\frac32x\) + 1

= (-\(\frac{x}{2}\))\(^3\) + 3.(-\(\frac{x}{2}\))\(^2\).1 + 3(\(-\frac12\)\(x\) ).1\(^2\) + 1\(^3\)

= (\(\frac{-x}{2}+1\))\(^3\)

\(-\frac{x^3}{8}+\frac34x^2-\frac32x+1\)

\(=\left(-\frac12x\right)^3+3\cdot\left(-\frac12x\right)^2\cdot1+3\cdot\left(-\frac12x\right)\cdot1^2+1^3\)

\(=\left(-\frac12x+1\right)^3\)

grow of garden tên roblox à?

yes yes yes, nhưng bạn trả lời điiii :(

ciu voi

1 I usually walk to school.

2 She isn't sleeping now.

3 They was arrive late yesterday.

4 Is he watching TV at the moment?

5 We aren't having class next Monday.

6 My mom cooks dinner every evening.

7 Do you go to the cinema last weeked?

8 Listen! Someone is knocking at the door.

9 I think she pass the test.

10 They don't eat meat on Fridays.

+) The teacher is explaining a new lesson to us.

(–) The teacher is not explaining a new lesson to us.

(?) Is the teacher explaining a new lesson to us?

cho mình tick nhé !

dùng v ing nhé