K
Khách

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

22 tháng 12 2021

I have a daughter and she has a great 👍 and she will be my first daughter to me that she was the best friend to me ever and would be the love ❤️ daughter dbest and and the best daughter daughter ever and for the world 🌎 daughter daughter and a sister of the year she said that she is not as good 😊 as she was a mother daughter of a woman of a young lady and a great 👍 daughter of the world 🌎 and daughter daughter of the daughter daughter of a young man who is also a great 👍 for a great daughter a great 👍 and daughter daughter of the daughter daughter and the grandmother Yen 💴 said she had a chance for the next book 📚 daughter who had a great 👍 of daughter daughter who had been on a trip home 🏡 and the mother daughter daughter and the granddaughter of a young lady of our family who was also a daughter and mother a daughter and mother of the daughter daughter and the holy land and she is the only one ☝️ of all the women that she has ever been able for which she was able for a daughter and daughter who was born on their daughter or mother the daughter and mother of daughter daughter and niece who was also a member for an early age and was a great 👍 for her daughter the daughter and a daughter and mother daughter and the family she is the only daughter I have and she is a very strong person and a daughter and I have been your own mother for years she said and that she was not the person that had the daughter of daughter daughter or daughter who is 😎Right now I'm just not a good friend and confidant is cool 😎 said that the daughter was not an American and she came cofe of course she is not an aunt or daughter or mother or any of the things she is doing to her she is the daughter and she is the daughter daughter who is a great 👍 daughter daughter and a great 👍 mother a daughter of the daughter and young lady who was the first daughterdaughter  of a woman of the daughter and daughter the holy land and she came a woman with daughter daughter who had a mother and a daughter and daughter Wyoming daughter of a woman who is not the only i daughter of the church who had a niece daughter and daughter of a church who was a daughter of daughter grandmother 👵 grandmother 👵 daughter and niece 💴😡the aunt and niece of a woman and she was the only one that was able she was a lady who had the best chance to live on world 🌎 by now and she is the only person who has been the best of daughter daughter of daughter to a woman and a great 👍 mother and she came a lot more of their own lives she ho and a daughter and she your own family 👨‍👩‍👧‍👦 the fact is she is the best daughter ever and she came a daughter of a woman who had a lot more than that I have ever had to do and I had no idea 💡 what is your favorite part about this game you can get the game 👼🏻☺️The daughter and she had a daughter daughter of daughter who had a daughter and she is a very very special and very very little girl who never 

21 tháng 12 2021

Ta có :

\(tanx=2=x=90^0\)

HT

21 tháng 12 2021

đổi 24p= 2/5 giờ, 18p=3/10 giờ

gọi độ dài quãng đường AB là x (km) (x>0)

thời gian xe dự định đi từ A đến B là: x/50 ( giờ) 

độ dài quãng đường đầu xe đi được là : 50. 2/5= 20 (km/h)

=> độ dài quãng đường còn lại là x-20(km/h) 

thời gian đi đoạn đường xấu lúc sau là : (x-20)/40 ( giờ) 

ta có phương trình: 2/5 + (x-20)/40= x/50 + 3/10

<=> ...<=> x =80( km)(thỏa mãn0

vậy quãng đường AB dài 80km

21 tháng 12 2021

x2 + 2x + 1 = (x + 2). căn bậc 2 của x2 + 1

Vậy ta có:

(x2 + 2x + 1) . (x2 + 1) = (x + 2).(x2 + 1)

(x2 + 2x + 1) . (x2 + 1) = x.(x2 + 1) + 2.(x2 + 1)

(x2 + 2x + 1) . (x2 + 1) = x3 + x + 2x2 + 2

= x2.(x2 + 1) + 2x.(x2 + 1) + x2 + 1 = x3 + x + 2x2 + 2

= x4 + x2 + 2x3 + 2x + x2 + 1 = x3 + x + 2x2 + 2

= x4 + 2x2 + 2x + 2x3 + 1 = x3 + x + 2x2 + 2

= x4 + 2x + 2x3 + 1 = x3 + x + 2

DD
21 tháng 12 2021

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

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

\(\Leftrightarrow x^2-3=\left(x+2\right)\frac{x^2+1-4}{\sqrt{x^2+1}+2}\)

\(\Leftrightarrow\orbr{\begin{cases}x^2-3=0\\1=\frac{x+2}{\sqrt{x^2+1}+2}\end{cases}}\)

\(\Leftrightarrow x^2-3=0\)

\(\Leftrightarrow x=\pm\sqrt{3}\)

21 tháng 12 2021

a, Hoành độ giao điểm (P) ; (d) thỏa mãn pt 

\(x^2=2x-m\Leftrightarrow x^2-2x+m=0\)

Để pt có 2 nghiệm pb khi \(\Delta'=1-m>0\Leftrightarrow m< 1\)

Vậy với m < 1 thì (P) cắt (d) tại 2 điểm pb 

b, Theo Vi et \(\hept{\begin{cases}x_1+x_2=2\\x_1x_2=m\end{cases}}\)

Ta có : \(\frac{1}{x_1^2}+\frac{1}{x_2^2}=2\Leftrightarrow\frac{x_1^2+x_2^2}{x_1^2x_2^2}=2\)

\(\Leftrightarrow\frac{\left(x_1+x_2\right)^2-2x_1x_2}{\left(x_1x_2\right)^2}=2\)Thay vào ta có : 

\(\Leftrightarrow\frac{4-2m}{m^2}=2\Leftrightarrow4-2m=2m^2\Leftrightarrow2m^2+2m-4=0\)

mà a + b + c = 0 => 2 + 2 - 4 = 0 

vậy pt có 2 nghiệm 

\(m_1=1\left(ktm\right);m_2=-2\left(tm\right)\)

20 tháng 12 2021

one cộng one bằng two

two cộng one bằng three ok

21 tháng 12 2021

Áp dụng BĐT Cô-si cho hai số dương x và y, ta có: \(\sqrt{xy}\le\frac{x+y}{2}\)

\(\Leftrightarrow\sqrt{xy}+y\le\frac{x+y}{2}+y=\frac{x+y+2y}{2}=\frac{x+3y}{2}\)

\(\Leftrightarrow\frac{x+3y}{\sqrt{xy}+y}\ge\frac{x+3y}{\frac{x+3y}{2}}=2\)

Dấu "=" xảy ra khi \(x=y\)

Vậy GTNN của P là 2 khi \(x=y\)