Hi

f(x) = x^4 + 2x^3 - 252x^2 - 54

f' = x(4x^2 + 6x - 504) = x(4 - 42)(x  + 12)

x = -12, 0 , 10.5

f(x) is decreasing when x < -12   and  when 0 < x < 10.5 

RELATED QUESTIONS

f(x) = x^3 − 2x^2 − 4x + 8 / x − 2
Find any hole(s) in the graph of f.
 (answered by greenestamps)

Find an interval over which the functio 
F(x)=-(x+5)^2(x-4)^3  is... (answered by Boreal)

Find an interval over which the function f(x)=(x+5)^3(x-4)^2 is decreasing.


 (answered by KMST)

F(x)=(3/(6+x))-3sin((1/2x)+5)
Where is the function increasing and decreasing, use... (answered by ikleyn)

For f(x)=1/x^2-2x-8  , find the interval(s) where f(x) <... (answered by khwang)

For f(x)= 1/x^2-2x-8, find the interval(s) where... (answered by Nate)

Given quadratic function:
{{{F(x)= -3(x-2)^2+1}}}
Find the following:
Vertex:
Axis of  (answered by stanbon)

f(x)=x^2+6x+4

1. Find the vertex
2. State the range of the function
3. On what... (answered by lwsshak3)

For the following equation, find the interval(s) where {{{f(x)<0}}}.... (answered by Edwin McCravy)