Consider the function f(x) = x4/3 − 4x1/3. Homework Help ✎
Algebraically determine where f is increasing.
Algebraically determine whether f is concave up or concave down at x = −1.
Determine the x-coordinates of all points of inflection.
Where is f '(x) positive?
Solve f ''(x) > 0 and f ''(x) < 0.
An inflection point occurs where f ''(x) undergoes a sign change.
Sometimes that happens where f ''(x) = 0 and sometimes where f ''(x) = DNE.