Textbook Consider the function f(z) = 1-7z on the interval [-3, 3]. Find the average or mean slope of the function on this interval, i.e. f(3)-(-3) 3-(-3) = By the Mean Value Theorem, we know there exists a c in the open interval (-3, 3) such that f'(c) is equal to this mean slope. For this problem, there is only one c that works. Find it.