f*f (x)
daca prin " * " intelegi "inmultit" , si prin "o" intelegi 0, relatia devine
(x+a) * (x+a)=0
deci
x+a=0
a=-x
dar atunci a nu e numar, e variabila si
f(x)=x+a=x-x=0
functia connstanta f(x) =0 ∀x∈R
dac prin '*" integi compus
f(f(x))= f(x+a) =x+a+a=x+2a
x+2a=0 ∀x∈R⇒a=-x/2 tot variabila
f(x) =x-x/2=x/2
f(f(x))=f(x/2) =x/2-x/2=0 iarasi functia constanta f(f(x))=0 de data asta la compunerea lui f cu f
probabil text gresit
