Let $h$ be a function having derivatives of all orders for $x > 0$. Selected values of $h$ and its first four derivatives are indicated in the table below. The function $h$ and these four derivatives are increasing on the interval $1 \leq x \leq 3$.
| $x$ | $h ( x )$ | $h ^ { \prime } ( x )$ | $h ^ { \prime \prime } ( x )$ | $h ^ { \prime \prime \prime } ( x )$ | $h ^ { ( 4 ) } ( x )$ |
| 1 | 11 | 30 | 42 | 99 | 18 |
| 2 | 80 | 128 | $\frac { 488 } { 3 }$ | $\frac { 448 } { 3 }$ | $\frac { 584 } { 9 }$ |
| 3 | 317 | $\frac { 753 } { 2 }$ | $\frac { 1383 } { 4 }$ | $\frac { 3483 } { 16 }$ | $\frac { 1125 } { 16 }$ |
(a) Write the first-degree Taylor polynomial for $h$ about $x = 2$ and use it to approximate $h ( 1.9 )$. Is this approximation greater than or less than $h ( 1.9 )$ ? Explain your reasoning.
(b) Write the third-degree Taylor polynomial for $h$ about $x = 2$ and use it to approximate $h ( 1.9 )$.
(c) Use the Lagrange error bound to show that the third-degree Taylor polynomial for $h$ about $x = 2$ approximates $h ( 1.9 )$ with error less than $3 \times 10 ^ { - 4 }$.