[tex]\text{Daca }A(a+1,a-1)\in G_f ,\text{ atunci e clar ca }f(a+1)=a-1\\f(a+1)=2(a+1)-3=2a+2-3=2a-1\\\text{Ramane sa rezolvam ecuatia:}\\2a-1=a-1\\\boxed{\boxed{a=0}}[/tex]
f:R→R a.i. f(x)=2x-3 .
A(a+1,a-1)∈G f <=> f(a+1)=a-1 <=> 2·(a+1)-3=a-1 => 2a-1=a-1 => a=0 .
