Question

Pe multimea numerelor reale se defineste legea de compozitie asociativa
x°y=1/2(x-3)(y-3)+3
a) Calculati: 1°2°3°…°2015

Answer 1

x*y=1/2(x-3)(y-3)+3, deci 1*2*3*4*...*2015=1/2(1-3)(2-3)(3-3)(4-3)....(2015-3)+3=3, deoarece paranteza (3-3)=0, tot produsul e =0 siramane 3.