Chain Rule with Table-Defined Functions

Use the chain rule to evaluate derivatives of compositions f(g(x)) or related expressions where f and g are defined only through a table of values.

ap-calculus-ab 2007 Q3 View
The functions $f$ and $g$ are differentiable for all real numbers, and $g$ is strictly increasing. The table below gives values of the functions and their first derivatives at selected values of $x$.
$x$$f(x)$$f^{\prime}(x)$$g(x)$$g^{\prime}(x)$
16425
29231
310-442
4-1367

The function $h$ is given by $h(x) = f(g(x)) - 6$.
(a) Explain why there must be a value $r$ for $1 < r < 3$ such that $h(r) = -5$.
(b) Explain why there must be a value $c$ for $1 < c < 3$ such that $h^{\prime}(c) = -5$.
(c) Let $w$ be the function given by $w(x) = \int_{1}^{g(x)} f(t)\, dt$. Find the value of $w^{\prime}(3)$.
(d) If $g^{-1}$ is the inverse function of $g$, write an equation for the line tangent to the graph of $y = g^{-1}(x)$ at $x = 2$.