Question

f : R ---> R, f(x) = x- 5 . Verificati daca P(0,5) si Q(5,0) apartine Gf

Answer 1

P(0,5)⇒x=0 si f(x)=5
f(0)=0-5⇒f(x)=-5 deci P ∈Gf
Q(5,0)⇒x=5 si f(x)=0
f(5)=5-5⇒f(x)=0⇒Q apartine Gf

Answer 2

P(0,5)∈Gf rezulta f(0)=5
                          f(0)=-5
Din ambele rezulta 5≠-5 deci P(0,5)∉Gf
Q(5,0)∈Gf rezulta f(5)=0
                            f(5)=0
Dinambele rezulta 0=0 deci Q(5,0)∈Gf