Suppose the only information you have about a function $f$ is that $f(1)=-2$ and the graph of its derivative as shown!.

$($a$)$ Use a linear approximatrion to estimate $f(0\mathrm{.}9)$ and $f(1\mathrm{.}1).$

$($b$)$ Are your estimates in part $($a$)$ too large or too small? Explain.