Let x, y, Z ∈ R +. Prove that (1 + x2) (1 + Y2) (1 + Z2) ≥ 8xyz

Let x, y, Z ∈ R +. Prove that (1 + x2) (1 + Y2) (1 + Z2) ≥ 8xyz

It is proved that: ∵ 1 + X & sup2; ≥ 2x, 1 + Y & sup2; ≥ 2Y, 1 + Z & sup2; ≥ 2Z
∴(1+x²)(1+y²)(1+z²)≥2x×2y×2z
That is, (1 + X & sup2;) (1 + Y & sup2;) (1 + Z & sup2;) ≥ 8xyz