Let f be a continuous function on an open interval I that contains a fixed real number a. Let h be a differentiable function on I with h(x)=a for all x∈I. Define the accumulation function
G(x)=∫h(x)af(t)dt,x∈I.
Answer the following questions about G.
(a) Determine G′(x) in terms of f, h, and h′(x).
(b) Provide a clear, logical explanation for the appearance of the overall sign in your expression for G′(x), making explicit reference to the change of limits in the definite integral.
(c) State the hypotheses on f and h that guarantee the differentiability of G on I. Justify each condition you list.