[tex]\tt\displaystyle \bigg{|}\frac{x^2-x-2}{x^2-4x+3}\bigg{|}=a\cdot\frac{x^2-x-2}{x^2-4x+3}\\\\\\\\a = -9\cdot f'(0)\\\\\\f(z) = \frac{z^2 - 1}{z-3}[/tex]