\(y'=2016x^{2015}.\left(x^2+1\right)^{2017}+2017\left(x^2+1\right)^{2016}.2x.x^{2016}\)
\(y'=x^{2015}\left(x^2+1\right)^{2016}\left(2016\left(x^2+1\right)+2017.2x^2\right)\)
\(y'=x^{2015}\left(x^2+1\right)^{2016}\left(2016x^2+2016+2017.2x^2\right)\)
\(y'=0\Rightarrow x=0\)
Hàm số có 1 cực trị duy nhất