Let $f(x)= \dfrac{ 2 x^2}{x^2+3}$

Below, type none if there are none.

Input the interval(s) on which $f$ is increasing.

Input the interval(s) on which $f$ is decreasing.

Find the point(s) at which $f$ achieves a local maximum.

Find the point(s) at which $f$ achieves a local minimum.

Find the interval(s) on which $f$ is concave up.

Find the interval(s) on which $f$ is concave down.

Find all inflection points.