Cho a,b,c>0
CMR:
\(\dfrac{bc}{a^2b+a^2c}+\dfrac{ca}{ab^2+b^2c}+\dfrac{ab}{ac^2+bc^2}\text{≥}\dfrac{1}{2}\left(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}\right)\)
cho a,b,c>0
CMR: a^3/b + b^3/c + c^3/a >= ab + bc + ca
Cho ba số a, b, c đề khác 0 và a2 + b2 + c2 - ab - bc - ca = 0
CMR: ( 1 + \(\dfrac{a}{b}\) ) ( 1 + \(\dfrac{b}{c}\) ) ( 1 + \(\dfrac{c}{a}\) ) = 8
a,cho (a+b+c)^2 =3(ab+ac+bc)
cmr:a=b=c
b,Cho(a-b)^2+(b-c)^2+(c-a)^2 +4(ab+bc+ca)=4(a^2+b^2+c^2)
cmr:a=b=c
Cho (a-b)^2+(b-c)^2+(c-a)^2+4(ab+bc+ac)>=4(a^2+b^2+c^2)
CMR: a=b=c
cho a+b+c=0 cmr a^4+b^4+c^4=2(ab+bc+ac)^2
cho a+b+c=0 cmr a^4+b^4+c^4=2(ab+bc+ac)^2
cho a+b+c=0
Chứng minh \(a^4+b^4+c^4\)=2\(\left(ab+ac+bc\right)^2\)
Gấp!!
Cho (a-b)^2+(b-c)^2+(c-a)^2+4(ab+ac+bc)=4(a^2+b^2+c^2). Chứng minh rằng: a=b=c
cho a,b,c duong , a+b+c=1
a, tim Min A=1/(a^2+b^2) +1/(b^2+c^2) +1/(c^2+a^2) +1/ab +1/bc +1/ac
b, tìm Min B=1/(a^2+bc) +1/(b^2+ac) +1/(c^2+ab) +1/ab +1/bc +1/ac