notam [tex] x^{2} +x+1 [/tex] cu a.
=> f(x) devine [tex] \frac{a(a+1)-6}{(a+1)(a+2)-2} [/tex]
=> f(x) = [tex] \frac{ a^{2}+a-6 }{ a^{2} +3a} [/tex]
=> f(x) = [tex] \frac{(a+3)(a-2)}{a(a+3)} [/tex]
=> f(x) = [tex] \frac{a-2}{a} [/tex]
inlocuim a
=> f(x) = [tex] \frac{ x^{2} +x-1}{ x^{2} +x+1} [/tex]
