Consider the function f(x)=12x5+60x4100x3+2\displaystyle {f{{\left({x}\right)}}}={12}{x}^{{5}}+{60}{x}^{{4}}-{100}{x}^{{3}}+{2}. For this function there are four important intervals: (,A]\displaystyle {\left(-\infty,{A}\right]}, [A,B]\displaystyle {\left[{A},{B}\right]},[B,C]\displaystyle {\left[{B},{C}\right]}, and [C,)\displaystyle {\left[{C},\infty\right)} where A\displaystyle {A}, B\displaystyle {B}, and C\displaystyle {C} are the critical numbers.
Find A\displaystyle {A}  
and B\displaystyle {B}  
and C\displaystyle {C}  

At each critical number A\displaystyle {A}, B\displaystyle {B}, and C\displaystyle {C} does f(x)\displaystyle {f{{\left({x}\right)}}} have a local min, a local max, or neither? Type in your answer as LMIN, LMAX, or NEITHER.
At A\displaystyle {A}
At B\displaystyle {B}
At C\displaystyle {C}