Cho a,b,c>0 chứng minh \(\frac{a}{b\:\:}+\frac{b}{c}+\frac{c}{a}\ge\frac{a+b}{c+a}+\frac{b+c}{a+b}+\frac{c+a}{b+c}\)
1) Cho a, b, c > 0. Chứng minh: \(\left(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\right)^2\ge\left(a+b+c\right)\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)\)
2) Cho \(a,b,c\in R\).
a) Chứng minh: \(\left(a^2+3\right)\left(b^2+3\right)\left(c^2+3\right)\ge4\left(a+b+c+1\right)^2\)
b) Chứng minh: \(\left(a^2+1\right)\left(b^2+1\right)\left(c^2+1\right)\ge\frac{5}{16}\left(a+b+c+1\right)^2\)
3) Cho \(a,b,c\in R\)Chứng minh: \(\frac{a^3}{b^2}+\frac{b^3}{c^2}+\frac{c^3}{a^2}\ge\frac{a^2}{b}+\frac{b^2}{c}+\frac{c^2}{a}\)
Cho a,b,c>0. Chứng minh rằng:
\(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\ge\frac{a+b}{b+c}+\frac{b+c}{a+b}+1\)
Cho a,b,c>0. Chứng minh rằng:
\(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\ge\frac{a+b}{b+c}+\frac{b+c}{a+b}+1\)
Cho A, B, C >0 chứng minh
\(\left(\frac{A}{B}+\frac{B}{C}+\frac{C}{A}\right)^2\ge\left(A+B+C\right)\left(\frac{1}{A}+\frac{1}{B}+\frac{1}{C}\right)\)
Cho a,b,c>0. Chứng minh rằng:
\(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\ge\frac{a+b}{b+c}+\frac{b+c}{a+b}+1\)
Cho a,b,c>0. Chứng minh rằng:
\(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\ge\frac{a+b}{b+c}+\frac{b+c}{a+b}+1\)
Cho a,b,c>0 ; a+b+c \(\ge\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\)
Chứng minh rằng : \(\frac{a}{b}+\frac{b}{c}+\frac{c}{a}\ge\frac{1}{ab}+\frac{1}{bc}+\frac{1}{ca}\)
Cho a>0, b>0, c>0, chứng minh rằng\(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\ge\frac{9}{a+b+c}\)