Question

Dada a P.G.(2,1,...)determine a fórmula do termo geral dessa P.G.

Answer 1

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$a_n=? \\ a_1=2 \\ n=n \\ r=q= \frac{1}{2} \\ \\ a_n=a_1.q^{n-1} \\ \\ a_n=2.( \frac{1}{2} )^{n-1} \\ \\ a_n=2.(2^{-1})^{n-1} \\ \\ a_n=2.2^{-n+1} \\ \\ a_n=2^{1-n+1} \\ \\ a_n=2^{2-n}$