Nó là điểm Q

Đơn giản là kĩ năng đọc đường tròn lượng giác

\(\dfrac{7\pi}{4}\) thì từ gốc A quay theo chiều kim đồng hồ 1 góc 45 độ sẽ được \(\dfrac{7\pi}{4}\)

Đề bài là gì thế bạn?

đề kìa :

X⁴ + 2x³ + 5x² + 4x - 12 = ?

Bài 1:

3: ĐKXĐ: x>=1

\(x-\sqrt{x+3+4\sqrt{x-1}}=1\)

=>\(x-\sqrt{x-1+2\cdot\sqrt{x-1}\cdot2+4}=1\)

=>\(x-\sqrt{\left(\sqrt{x-1}+2\right)^2}=1\)

=>\(x-\left|\sqrt{x-1}+2\right|=1\)

=>\(x-\left(\sqrt{x-1}+2\right)=1\)

=>\(x-\sqrt{x-1}-2-1=0\)

=>\(x-1-\sqrt{x-1}-2=0\)

=>\(\left(\sqrt{x-1}\right)^2-2\sqrt{x-1}+\sqrt{x-1}-2=0\)

=>\(\left(\sqrt{x-1}-2\right)\left(\sqrt{x-1}+1\right)=0\)

=>\(\sqrt{x-1}-2=0\)

=>\(\sqrt{x-1}=2\)

=>x-1=4

=>x=5(nhận)

Bài 1:

a. \(=2\sqrt{3^2}+\sqrt{15}-\sqrt{4.15}=6+\sqrt{15}-2\sqrt{15}=6-\sqrt{15}\)

b. \(=5\sqrt{10}+2\sqrt{5^2}-\sqrt{25.10}=5\sqrt{10}+10-5\sqrt{10}=10\)

c. \(=\left(\sqrt{4.7}-\sqrt{4.3}-\sqrt{7}\right)\sqrt{7}+2\sqrt{21}\)

\(=2\sqrt{7^2}-2\sqrt{21}-\sqrt{7^2}+2\sqrt{21}=7\)

d. \(=\left(\sqrt{9.11}-\sqrt{9.2}-\sqrt{11}\right)\sqrt{11}+3\sqrt{22}\)

\(=\left(3\sqrt{11}-3\sqrt{2}-\sqrt{11}\right)\sqrt{11}+3\sqrt{22}\)

\(=3\sqrt{11^2}-3\sqrt{22}-\sqrt{11^2}+3\sqrt{22}=22\)

Bài 3:

a.

\(=\left(1-\sqrt{x}\right)\left(1+\sqrt{x}+\sqrt{x}^2\right)=1-\sqrt{x}^3=1-x\sqrt{x}\)

b.

\(=\left(\sqrt{x}+2\right)\left(\sqrt{x}^2-2\sqrt{x}+2^2\right)=\sqrt{x}^3+2^3=x\sqrt{x}+8\)

c.

\(=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}^2+\sqrt{xy}+\sqrt{y}^2\right)=x\sqrt{x}-y\sqrt{y}\)

d.

\(=\left(x+\sqrt{y}\right)\left(x^2-x\sqrt{y}+\sqrt{y}^2\right)=x^3+y\sqrt{y}\)

It was said that many people were homeless after the flood.

Many people were said to be homeless after the flood.

It was thought that the company was badly damaged by the fire.

The company was thought to have been badly damaged by the fire.

\(d\left(M;\left(ABCD\right)\right)=\dfrac{1}{2}d\left(S;\left(ABCD\right)\right)=\dfrac{a}{2}\)

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