$[-/8$ Points$]$

SCALC$91\mathrm{.}8\mathrm{.}025.$

Consider the following function.

$f(x)=\frac{x-4}{x^2-16}$

$($a$)$ Explain why $f$ has a removable discontinuity at $x=4.($Select all thot apply.$)$

$f(4)$ and $\underset{x4}{lim}f(x)$ exist, but are not equal.

$f(4)$ is undefined.

$\underset{x4}{lim}f(x)$ exists.

$\underset{x4}{lim}f(x)$ does not exists.

none of the above

$($b$)$ Redefine $f(4)$ so that $f$ is continuous at $x=4($and thus the discontinuity is "removed"$).$

$f(4)=$

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