Consider the function f(x)=12x^5+60x^4−100x^3+4. For this function there are four important intervals: (−INF,A], [A,B] ,[B,C] , and [C,INF) where A, B, and C are the critical numbers. Find A, B, and C.

Question

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

Sorry to post another question but I have problems with this one too...

Answer 1

For B I have 0 and for C 1

I guess A will be local max B will be the local neither, c local min

I don't know which will be the value of A because when I graph it, it's actually a value really close to 0, and I have pluged, -1, -0.1, -0.2, -0.3 and -0.5 but none of them are the answer

Answer 2

A=-5