Áp dụng BĐT `Cauchy-schwars`
`P=(y^2+z^2)/x^2+x^2(1/y^2+1/z^2)+2016`
`P\ge (y^2+z^2)/x^2+(4x^2)/(y^2+z^2)+2016`
`P\ge [(y^2+z^2)/x^2+x^2/(y^2+z^2)]+(3x^2)/(y^2+z^2)+2016`
`P\ge 2+3+2016=2021`
Dấu `=` xảy ra `⇔x/\sqrt2=y=z`
Vậy $Min_P=2021⇔\dfrac{x}{\sqrt{2}}=y=z$