Question

Fie a= 1/5 + 1/6 + .............. + 1/17
Aratati ca a ∈ (1,2)

Multumesc anticipat!

Answer 1

1/5+1/6+………+1/17=1+1/5+1/6+…..+1/17-1=1/18-1 supraveghere 1/18-1={1,2}