30. Let f(x) be the function defined by f (x) = In x - x. Find the value of c for which the instantaneous rate of change of f(x) at x = c is the same as the average rate of change of f(x) over [1, 5]. a) -0.598 b ) 1 c) 2.485 d) -2.391 e) -1 31. If G(x) and g(x) are continuous functions such that G'(x) = g(x) for all x, then Sag(x) dx = a) G'(a) - G' (b ) b) G' (b) - G'(a) c) G(a) - G(b) d) G(b) - G(a) e) none of these 32. Let f(x) be the function given by f(x) = 5x ex. For what values of x is f(x) concave upward? a ) x > - 2 b) x -1 d) x0 33. The graph of a piecewise linear function f(x), for -1