Question

Va rog seriozitate.

Answer 1

a=1 +1/2 +2/3 +...+2²⁰¹⁵ /2²⁰¹⁵ +1 <=> a=1 +(2/2 -1/2) +(3/3 -1/3) +...+(2²⁰¹⁵ +1 /2²⁰¹⁵ +1  -1/2²⁰¹⁵) <=> a=1+1+1+...+1 (de 2²⁰¹⁵ +1 ori) -(1/2 +1/3 +...+1/2²⁰¹⁵) <=> a=2²⁰¹⁵ +1 -(1/2 +1/3 +...+1/2²⁰¹⁵) => 2²⁰¹⁵ +1∈N dar 1/2 +1/3 +...+1/2²⁰¹⁵∉N <=> a∉N . (diferenta dintre un numar natural si unul rational va fi un numar rational) .