Find the solutions of second derivative

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If $$f(x)=\frac {2x}{x^{2}-3x+2}$$ find the solutions of $$f''(x)=0$$ This problem is from a test. Is it possible to solve this without a calculator and without hard work? Maybe this fraction can be decomposed somehow? I have the same question for this function $$g(x)=\frac{\sqrt{x^2-1}}{x-2}$$

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Partial fractions give

$$f(x) = \frac{-2}{x-1} + \frac{4}{x-2}.$$

Then

$$f''(x) = \frac{-4}{(x-1)^3} + \frac{8}{(x-2)^3}.$$

The numerator of that, after you add the fractions is $x^3-6x+6,$ which doesn't have pretty roots. The real root is $-(\sqrt[3]{4}+\sqrt[3]{2}).$