Cho \(\frac{x^2}{y+z}+\frac{y^2}{z+x}+\frac{z^2}{x+y}=\)0 ( x + y + z \(\ne\)0 )
CMR : \(\frac{x}{y+z}+\frac{y}{z+x}+\frac{z}{x+y}=1\)
Cho \(\frac{x^2}{y+z}+\frac{y^2}{z+x}+\frac{z^2}{z+x}=\)0 ( x + y + z \(\ne\)0 )
CMR : \(\frac{x}{y+z}+\frac{y}{z+x}+\frac{z}{x+y}=1\)
xét 2 biểu thức: \(P=\frac{x}{y+z}+\frac{y}{z+x}+\frac{z}{x+y}\)
\(Q=\frac{x^2}{y+z}+\frac{y^2}{z+x}+\frac{z^2}{x+y}\)
cmr: nếu P=1 thì Q=0
Cho x,y,z>0.Cmr
\(\frac{x^2}{y^2}+\frac{y^2}{z^2}+\frac{z^2}{x^2}\ge\frac{x}{y}+\frac{y}{z}+\frac{z}{x}\)
bài 1) CMR
a) (x+y)(y+z)(z+x)=0 (x;y;z#0)
thì \(\frac{1}{x}+\frac{1}{y}+\frac{1}{z}=\frac{1}{x+y+z}\)
b) cho \(\frac{x}{a}+\frac{y}{b}+\frac{z}{c}=1và\frac{a}{x}+\frac{b}{y}+\frac{c}{z}=0\)
chứng minh \(\frac{x^2}{a^2}+\frac{y^2}{b^2}+\frac{z^2}{c^2}=1\)
gần gấp!!!!!!
Cho \(x,y,z>0\)
CMR: \(\frac{x}{z^2+y^2}+\frac{y}{x^2+y^2}+\frac{z}{x^2+y^2}\le\frac{1}{2}\left(\frac{1}{x}+\frac{1}{y}+\frac{1}{z}\right)\)
Cho \(\frac{1}{x}+\frac{1}{y}+\frac{1}{z}=0.\)CMR biểu thức sau luôn âm với mọi x với x,y,z khác 0
\(A=\left(\frac{x^2+y^2}{x^2y^2}-\frac{1}{z^2}\right)\left(\frac{x^2+z^2}{x^2z^2}-\frac{1}{y^2}\right)\left(\frac{y^2+z^2}{y^2z^2}-\frac{1}{x^2}\right)\)
cho x , y , z > 0 . CMR : \(\frac{x^2-z^2}{y+z}+\frac{y^2-x^2}{z+x}+\frac{z^2-y^2}{x+y}\ge0\)
Giải giúp mình với
CMR \(\frac{y-z}{\left(x-y\right).\left(x-z\right)}+\frac{z-x}{\left(y-z\right).\left(y-x\right)}+\frac{x-y}{\left(z-x\right).\left(z-y\right)}=\frac{2}{x-y}+\frac{2}{y-z}+\frac{2}{z-x}\)Cho a,b,c,x,y,z \(\ne\)0 và \(a+b+c=x+y+z=\frac{x}{a}+\frac{y}{b}+\frac{z}{c}\)CMR \(a^2x+b^2y+c^2z=0\)Thanks nhiều ạ