Các câu hỏi tương tự
H24
3 tháng 10 2021 lúc 9:15
Cho 3 số thực a,b,c thỏa mãn: \(3\left(\dfrac{1}{a^2}+\dfrac{1}{b^2}+\dfrac{1}{c^2}\right)-2\left(\dfrac{1}{ab}+\dfrac{1}{bc}+\dfrac{1}{ca}\right)=404\)
Tìm MaxP \(=\dfrac{1}{\sqrt{5a^2+2ab+2b^2}}+\dfrac{1}{\sqrt{5b^2+2bc+2c^2}}+\dfrac{1}{\sqrt{5c^2+2ca+2a^2}}\)
Cho a,b,c>0 thỏa mãn ab+bc+ca=1. CMR:
\(\left(\dfrac{a}{\sqrt{a^2+1}}+\dfrac{b}{\sqrt{b^2+1}}+\dfrac{c}{\sqrt{c^2+1}}\right)^3\le\dfrac{3}{2}\left(\dfrac{1}{a^2+1}+\dfrac{1}{b^2+1}+\dfrac{1}{c^2+1}\right)\)
cho a,b,c>0;\(a+b+c,abc=1\).CMR
\(\dfrac{bc}{a^2\left(b+c\right)}+\dfrac{ca}{b^2\left(c+a\right)}+\dfrac{ab}{c^2\left(a+b\right)}\ge\dfrac{3}{2}\)
1. Cho a,b,c 0. CmR: dfrac{a^2+b^2}{a+b}+dfrac{b^2+c^2}{b+c}+dfrac{c^2+a^2}{c+a}le3.dfrac{a^2+b^2+c^2}{a+b+c}2. Cho fleft(xright)ax^2+bx+c biết rằng: hept{begin{cases}left|fleft(0right)right|le1left|fleft(-1right)right|le1left|fleft(1right)right|le1end{cases}}CmR: a) left|aright|+left|bright|+left|cright|le3 b) left|fleft(xright)right|ledfrac{5}{4}forall xinleft[-1;1right]
Đọc tiếp
1. Cho a,b,c > 0. CmR: \(\dfrac{a^2+b^2}{a+b}+\dfrac{b^2+c^2}{b+c}+\dfrac{c^2+a^2}{c+a}\le3.\dfrac{a^2+b^2+c^2}{a+b+c}\)
2. Cho \(f\left(x\right)=ax^2+bx+c\) biết rằng: \(\hept{\begin{cases}\left|f\left(0\right)\right|\le1\\\left|f\left(-1\right)\right|\le1\\\left|f\left(1\right)\right|\le1\end{cases}}\)
CmR: a) \(\left|a\right|+\left|b\right|+\left|c\right|\le3\)
b) \(\left|f\left(x\right)\right|\le\dfrac{5}{4}\forall x\in\left[-1;1\right]\)
H24
6 tháng 11 2021 lúc 15:26
Cho \(a^2+b^2+c^2+\left(a+b+c\right)^2\le4\)
CMR: \(\dfrac{ab+1}{\left(a+b\right)^2}+\dfrac{bc+1}{\left(b+c\right)^2}+\dfrac{ca+1}{\left(c+a\right)^2}\ge3\)
cho a,b,c>0
CMR:
1) \(a+b+\dfrac{1}{4}\ge\sqrt{a+b}\)
2) \(\left(a+b+\dfrac{1}{2}\right)^2+\left(b+c+\dfrac{1}{2}\right)^2+\left(c+a+\dfrac{1}{2}\right)^2\ge4\left(\dfrac{1}{\dfrac{1}{a}+\dfrac{1}{b}}+\dfrac{1}{\dfrac{1}{b}+\dfrac{1}{c}}+\dfrac{1}{\dfrac{1}{c}+\dfrac{1}{a}}\right)\)
Cho a,b,c là các số khác 0 thỏa a+b+c=0.Cmr:
\(\dfrac{a^4}{a^4-\left(b^2-c^2\right)^2}+\dfrac{b^4}{b^4-\left(c^2-a^2\right)^2}+\dfrac{c^4}{c^4-\left(a^2-b^2\right)^2}=\dfrac{3}{4}\)
H24
19 tháng 1 2022 lúc 22:35
Bài 1: CMR:
\(a,\dfrac{a}{b^2}+\dfrac{b}{c^2}+\dfrac{c}{a^2}\ge\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}\)
\(b,\dfrac{a^3}{b\left(2c+a\right)}+\dfrac{b^3}{c\left(2a+b\right)}+\dfrac{c^3}{a\left(2b+c\right)}\ge1\) với a+b+c=3
Bài 2: \(a,b,c\in N,a+b+c=2021\)
Tìm GTNN \(P=\dfrac{a}{b+c}+\dfrac{b}{c+a}+\dfrac{c}{a+b}\)
Cho a,b,c khác 0 thỏa mãn a\(\left(\dfrac{1}{c}+\dfrac{1}{b}\right)+b\left(\dfrac{1}{c}+\dfrac{1}{a}\right)+c\left(\dfrac{1}{a}+\dfrac{1}{b}\right)=-2\)
a(1b+1c)+b(1c+1a)+c(1a+1b)=−2
và a3+b3+c3=1. CMR \(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}=1\)