Question

Fie multimea A={-2,-1,0,1,2} si o functie bijectiva f:A->A. Sa se calculeze f(-2)+f(-1)+f(0)+f(1)+f(2)

Answer 1

f fiind bijectiva reiese ca {f(-2),f(-1),f(0),f(1),f(2)}={-2,-1,0,1,2}

f(-2)+f(-1)+f(0)+f(1)+f(2)=(-2)+(-1)+0+1+2(nu neaparat in ordinea asta)=0