Find $f^{\prime}(x)$ For the Function, Then Find $f^{\prime}(x)$ For the Given $x$
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Multiple Choice

Find $f^{\prime}(x)$ for the function, then find $f^{\prime}(x)$ for the given $x$ .
- $f(x) =-\frac{1}{3 x}, f^{\prime}(2)$

A) $f^{\prime}(x) =\frac{1}{3 x^{2}} ; f^{\prime}(2) =\frac{1}{12}$
B) $f^{\prime}(x) =3 x ; f^{\prime}(2) =6$
C) $f^{\prime}(x) =-\frac{1}{\left(3 x^{2}\right) } ; f^{\prime}(2) =-\frac{1}{12}$
D) $f^{\prime}(x) =3 x^{2} ; f^{\prime}(2) =12$