Question

calculando o limite da soma dos termo da P.G (3, 1, 1/3, 1/9,...) encontramos?

A) 5,4
B) 4,5
C) 6,5
D) 4,3
E) 5,8

Answer 1

Observe que:

r = 1/3

A soma dos termos será:

$\\ S_{n} = \frac{ a_{1} }{1-r} \\ \\ S_{n} = \frac{3}{1- \frac{1}{3} } \\ \\ S_{n} = \frac{3}{ \frac{3-1}{3} } \\ \\ S_{n} = \frac{3}{ \frac{2}{3} } \\ \\ S_{n} = 3* \frac{3}{2} \\ \\ S_{n} = \frac{9}{2} \\ \\ S_{n} = 4,5$