1+1 bằng mấy >:D
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
13 tháng 8 2017
Áp dụng BĐT Cô si ta có:
\(A=a+b+\frac{1}{a+b}\)
\(=\frac{1}{a+b}+\frac{a+b}{4}+\frac{3\left(a+b\right)}{4}\)
\(\ge2\sqrt{\frac{1}{a+b}\cdot\frac{a+b}{4}}+\frac{3\cdot2\sqrt{ab}}{4}\)
\(\ge2\cdot\frac{1}{2}+\frac{3\cdot2}{4}=\frac{5}{2}\)
Khi a=b=1
Chú ý viết đề cẩn thận hơn bằng cách click vào nút Σ nhé
NT
19 tháng 3 2018
Spring starts from January to March, and the season changes. In the spring the weather is very warm and pleasant. The sun shines the gentle sunbeams that make the trees sprout. Beautiful nature. Spring is how many beautiful flowers lilies, roses, peach blossom, apricot blossom. And so there are so many kinds of fruits. Maybe that is why spring is often called the wedding season, this fun next to the other. On New Year's Spring, he and his parents were lucky. Be with the family to welcome the warm New Year.I love the spring.
~Good luck to you~
LA
19 tháng 3 2018
Mid-Autumn Festival is under the full moon day of the lunar calendar every year in August, over 4,000 years ago. This is the day children’s festival, also known as the “Festival looks Moon”. Children are expected Tet is because adults are often donated toys, usually light. His star, mask, light pull troops … and pies, cakes plas. Besides the Tet Holiday, Mid-Autumn festival is one of the most famous festivals and it is a traditional celebration for Vietnamese children.
In this new year, we organized presentation deck, looks moon. Everywhere is fallen in the active and colorful air. Children are provided with many nice lanterns – star lanterns, flower lanterns and diverse funny masks for special performance in the evening of the full moon. In some areas, people also held dragon dance, lion dance to the children happy. The main point of the Mid-Autumn is that children use the beautiful lanterns, wear funny masks, perform fantas lion dances and sing folklore songs in the house’s grounds or on the streets when the moon is rising.
In Vietnam, Moon cakes are the specific cakes and are only on this festival. Moon cakes, which are made from flavor, dried fruit, meat, egg, pumpkin’s seed, peanut, are so sweet and good tasting. Moon cakes symbolize Luck, Happiness, Health and Wealth on the Mid-Autumn day.
Mid-Autumn celebration is also an opportunity for members of the family to get together and share everything in their year. The young generation express their gratitude to the old generation. The parents show their love for their children. For others, because the traditional time to have this festival is usually after harvesting the crops, it is as the congratulation for the full harvest.
Apart from moon cakes and lanterns, the other most visible tradition related to Mid-Autumn festival is the lion dance. On the nights leading up to the holiday, groups of children parade through the streets – some of the children maintain a martial beat on drums, while others control an extravagantly decorated ‘lion’ crafted from molds and paper.
The children approach homes and businesses and ask the owners for their permission to perform. If they agree, the children put on a show that is believed to bring a blessing of luck and fortune. Afterwards the host gives the children lucky money as a sign of gratitude.
FF
28 tháng 8 2016
3. abc > 0 nên trog 3 số phải có ít nhất 1 số dương.
Vì nếu giả sử cả 3 số đều âm => abc < 0 => trái giả thiết
Vậy nên phải có ít nhất 1 số dương
Không mất tính tổng quát, giả sử a > 0
mà abc > 0 => bc > 0
Nếu b < 0, c < 0:
=> b + c < 0
Từ gt: a + b + c < 0
=> b + c > - a
=> (b + c)^2 < -a(b + c) (vì b + c < 0)
<=> b^2 + 2bc + c^2 < -ab - ac
<=> ab + bc + ca < -b^2 - bc - c^2
<=> ab + bc + ca < - (b^2 + bc + c^2)
ta có:
b^2 + c^2 >= 0
mà bc > 0 => b^2 + bc + c^2 > 0
=> - (b^2 + bc + c^2) < 0
=> ab + bc + ca < 0 (vô lý)
trái gt: ab + bc + ca > 0
Vậy b > 0 và c >0
=> cả 3 số a, b, c > 0
3 tháng 5 2019
1.a, Ta có: \(\left(a+b\right)^2\ge4a>0\)
\(\left(b+c\right)^2\ge4b>0\)
\(\left(a+c\right)^2\ge4c>0\)
\(\Rightarrow\left[\left(a+b\right)\left(b+c\right)\left(a+c\right)\right]^2\ge64abc\)
Mà abc=1
\(\Rightarrow\left[\left(a+b\right)\left(b+c\right)\left(a+c\right)\right]^2\ge64\)
\(\Rightarrow\left(a+b\right)\left(b+c\right)\left(a+c\right)\ge8\left(đpcm\right)\)
21 tháng 5 2022
a: \(=\left(a-b\right)^2-\left(c+d\right)^2\)
\(=a^2-2ab+b^2-c^2-2cd-d^2\)
b: \(=\left(x+3z\right)^2-4y^2\)
\(=x^2+6xz+9z^2-4y^2\)
c: \(=\left(x^3-1\right)\left(x^3+1\right)=x^6-1\)
HT
9
21 tháng 2 2016
1 + 1 = 2 tui ko ngu
LƯU Ý
Các bạn học sinh KHÔNG ĐƯỢC đăng các câu hỏi không liên quan đến Toán, hoặc các bài toán linh tinh gây nhiễu diễn đàn. Online Math có thể áp dụng các biện pháp như trừ điểm, thậm chí khóa vĩnh viễn tài khoản của bạn nếu vi phạm nội quy nhiều lần.
Chuyên mục Giúp tôi giải toán dành cho những bạn gặp bài toán khó hoặc có bài toán hay muốn chia sẻ. Bởi vậy các bạn học sinh chú ý không nên gửi bài linh tinh, không được có các hành vi nhằm gian lận điểm hỏi đáp như tạo câu hỏi và tự trả lời rồi chọn đúng.
21 tháng 2 2016
sủa nhiều quá con Hồ Thị Thanh kia
1+1=2 nhé
bằng 3