Problema Recapitulativa clasele VIII-IX


1. Fie [tex]E_{n}= (1- \frac{4}{1})(1- \frac{4}{9})(1- \frac{4}{25})......(1- \frac{4}{(2n-1)^2}.

Aratati ca E_{n} = \frac{1+2n}{1-2n}

[/tex]


oricare ar fi n ∈ N*