Consider the function below f(x) = x3 − 12x + 3 find intervals of increase and decrease

Turning points are where the derivative is zero.
  f'(x) = 0 = 3x² -12
  0 = 3(x -2)(x +2)
The values of x that satisfy this are x=2, x=-2.

Since the coefficient of x³ is positive, we know the function is generally increasing left-to-right. It will have an interval of decrease between the turning points.

  increasing: (-∞, -2) ∪ (2, ∞)
  decreasing: (-2, 2)

At a constant it will take one hour to travel 32 mi.at that speed it will take 1/2 hr to travel the remaining 16 mi.it will take 1+1/2 hr to travel the 48mi @ 32mph.so 1 hr = 60 min& 1/2 hr = 30 min1+1/2 hr = 90 min.there are 60s in each 90 × 60 = 3600 seconds.the real question seriously is he why are they driving so slow? ! lol.