Question

For which intervals the graphs of the functions f(x) = x^3 + x^2 - 4x - 4 is positive

Answer 1

Step-by-step explanation:

Consider a function

f

(

x

)

which is twice differentiable. The graph of such a function will be concave upwards in the intervals where the second derivative is positive and the graph will be concave downwards in the intervals where the second derivative is negative. To find these intervals we need to find the inflection points i.e. the x-values where the second derivative is 0.