What have you tried?
f′(0) = f′(2) = f′(4) = 0,
The slope for f(x) at x=0, 2 and 5 is 0. That is the slope is horizontal. That is there is a max or min at these points.
f′(t) > 0 if t < 0 or 2< t < 4
The function f(x) is increasing on those intervals
f′(t) < 0 if 0 < t < 2 or t > 4
The function f(x) is decreasing on those intervals
f′′(t) > 0 if 1 < t < 3
f(x) is concave up on these intervals
f′′(t) < 0 if t < 1 or t > 3
f(x) is concave down on these intervals