Suppose f′(x) is a differentiable decreasing function for all x. in each of the following pairs, which number is the larger? give a reason for your answer. (a) f ′ ( 5 ) and f ′ ( 6 ) (b) f '' ( 5 ) and 0 (c) f ( 5 + δ x ) and f ( 5 ) + f ′ ( 5 ) δ x