f(x)=4x3−6x2−72xf(x) = 4x^3 - 6x^2 - 72xf(x)=4x3−6x2−72x. Where is fff increasing / decreasing?
Increasing everywhere.
Decreasing everywhere.
Increasing in (−∞,−2)(-\infty,-2)(−∞,−2), decreasing in (−2,∞)(-2,\infty)(−2,∞).
Increasing in (−∞,−2)(-\infty,-2)(−∞,−2) and (3,∞)(3,\infty)(3,∞), decreasing in (−2,3)(-2,3)(−2,3).
