`1/2=(x^2-x^2+1)/2≥\sqrt(x^2(1-x^2))`
`⇒(x^2)/(\sqrt(1-x^2))=(x^3)/(\sqrt(x^2(1-x^2)))≥2x^3`
tương tự :
`(z^2)/(\sqrt(1-z^2)≥2z^3`
`(y^2)/(\sqrt(1-y^2)≥2y^3`
`⇒(x^2)/(\sqrt(1-x^2))+(z^2)/(\sqrt(1-z^2))+(y^2)/(\sqrt(1-y^2))≥2x^3+2y^3+2z^3=2(x^3+y^3+z^3)=2.1=2`
`''=''`xẩy ra khi :
`x=y=z=1/(√3)`