4. This problem is about some function. All we know about thefunction is that it exists everywhere and we also know theinformation given below about the derivative of the function.Answer each of the following questions about this function. Be sureto justify your answers. f ′(−5) = 0 f ′(−2) = 0 f ′(4) = 0 f ′(8)= 0 f ′(x) < 0 on (−5,−2), (−2,4), (8,∞) f ′(x) > 0 on(−∞,−5), (4,8)
a. Identify the critical points of the function.
b. Determine the intervals on which the function increases anddecreases.
c. Classify the critical points as relative maximums, relativeminimums or neither.
