$x=2$ yazarsak denklem
$2f(2)-3f(\dfrac{1}{2})=4$. .. ............(1)
$x=\dfrac{1}{2}$ yazarsak denklem
$2f(\dfrac{1}{2})-3f(2)=\dfrac{1}{4}$...........(2)
1. Denklemi 3 , 2 denklemi 2 ile çarpıp taraf tarafa toplarsak
$-7f(\dfrac{1}{2})=\dfrac{49}{4}$
$f(\dfrac{1}{2})=\dfrac{-7}{4}$ elde edilir.