Derivative and Integral Transformations In the vector space $\mathcal{C}^{\infty}[a, b]$ of infinitely differentiable functions on the interval $[a, b]$, consider the derivative transformation $D$ and the definite integral transformation $I$ defined by
$$
D(f)(x)=f^{\prime}(x) \text { and } I(f)(x)=\int_a^x f(t) d t .
$$
(a) Compute $(D I)(f)=D(I(f))$.
(b) Compute $(I D)(f)=I(D(f))$.
(c) Do these transformations commute? That is to say, is it true that $(D I)(f)=(I D)(f)$ for all vectors $f$ in the space?
age of $T$ (that is, its range).