question_answer

Find the derivative of f(x) \[\left\{ \begin{matrix}    \frac{x-1}{2{{x}^{2}}-7x+5}\,\,\,, & when\,x\ne 1  \\    -\frac{1}{3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,, & when\,x=1  \\ \end{matrix} \right.\] at x=1

A)  \[\frac{1}{2}\]                         

B)  \[\frac{2}{9}\]

C)  \[\frac{-1}{2}\]                        

D)  \[\frac{-2}{9}\]

E)  None of these