Question

considere a pg (1,2,4,8,...) .calcule a soma dos 20 primeiros termos dessa pg , deixando indicado a potencia

Answer 1

S20 = a1 . (q^n - 1) / q - 1

S20 = 1 (2^20 - 1) / 2 - 1

S20 = 2^20 - 2^0

Answer 2

$Sn= \frac{a1.( q^{n}-1 }{q-1}$

$S20 = \frac{1.( 2^{20}-1) }{2-1} =\ \textgreater \ S20= \frac{1.(1048576-1)}{1}$

$S20= 1048575$

$Potencia= \ \textgreater \ 1048575 = 2^{20} - 2^{0} ok$