Question

f(x)= 2k+1

Demonstrati ca f(k) +f(k+1) = f(k+1) + f(k+2) pentru orice k apartinand lui R

Answer 1

f(x) = 2x+1

f(k) +f(k+1) = f(k+1) + f(k+2)

⇔ 2k+1+2(k+1)+1 = 2(k+1)+1+2(k+2)+1

⇔ 2k+1+2k+2+1 = 2k+2+1+2k+4+1

⇔ 4k+4 = 4k+8  (F)