Differentiate the function. r(z) = 2-8 - 21/2 r'(z) = Differentiate the function. || F'(z) = | A + Bz + Cz F(z) = Consider the following. Find f'(x). f'(x) = f(x)=x4-12x3 + 36x2 Compare the graphs of f and f' and use them to explain why your answer is reasonable. f'(x)=0 when f---Select--- f'(x) is positive when f---Select--- f'(x) is negative when f--Select---