[tex]G_f\cap Ox=\left\{A(a,0)\right\}\Rightarrow A(a,0)\in G_f\Rightarrow f(a)=0\Rightarrow\displaystyle\frac{2a^2+b+2}{2a}=0\Rightarrow 2a^2+b+2=0\\\\\\G_f\cap Oy=\left\{B\left(0,-\frac32\right)\right\}\Rightarrow B\left(0,-\displaystyle\frac32\right)\Rightarrow f(0)=\displaystyle-\frac32\Rightarrow \displaystyle\frac{b+2}{a}=-\frac32\Rightarrow -3a=2b+2\Rightarrow\displaystyle b=\frac{-3a-4}{2}\\\\2a^2+b+2=0\\\displaystyle 2a^2+\frac{-3a-4}{2}+2=0|\cdot2\\4a^2-3a-4+4=0[/tex]
[tex]4a^2-3a=0\Rightarrow a(4a-3)=0\Rightarrow a=0\text{ sau }4a-3=0\\\text{Dar }a\in\mathbb{R}^*\Rightarrow a=\displaystyle\frac{3}{4}\\\\b=\frac{-3a-4}{2}=\frac{-25}{8}[/tex]
