20 !
a polynomial function is shown below: f(x) = x3 − 3x2 − 4x + 12
which graph best represents the function?

F(x) = x3 − 3x2 − 4x + 12    ( should be   f(x) = x^3 − 3x^2 − 4^x + 12 )

is a cubic function because its highest power of x is 3.  Because x^3 is positive, the graph starts in Quadrant III and ends in Quadrant I.  

The y-intercept is (0,12).

The greatest possible number of real roots is 3; the minimum number of real roots is 1.

Note that x=3 is a root of this function f(x) = x^3 − 3x^2 − 4^x + 12.  Thus, (3,0) is an x-intercept.  x=2 and x= -2 are also roots and lead to zero y-intercepts.

Can you now choose the correct graph?

If not, ask questions and I'll try to help you further. 

It is 5.8 you add all of the up to equat 180 then solve the equation