Consider the function f(x)=x3−3x+2 on the closed interval [1,2].
a. (i) Calculate the average rate of change of f on the interval [1,2].
b. (ii) Obtain f′(x) from first principles or otherwise.
c. (iii) Find all numbers c in the open interval (1,2) for which f′(c) equals the average rate found in part (i). Show all necessary algebraic steps.