Question

40 PONTOS. Determine a soma dos termos das PG's infinitas:

a) (1/5, 1/10,...) b) (4/5, 2/5,...) c) (2/3, 4/9,...)

Answer 1

Resposta:

a) Sₙ = a₁

----------------

1 - q

q = 1/10/1/5 = 1/2

Sₙ = 1/5

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1 - 1/2

Sₙ = 1/5 / 1/2

Sₙ = 2/5

b)

q = 2/5/4/5 = 10/20 = 1/2

Sₙ = 4/5/1 - 1/2

Sₙ = 4/5 / 1/2

Sₙ = 8/5

c) q = 4/9/2/3 = 12/18 = 2/3

Sₙ = 2/3 / 1 - 2/3

Sₙ = 2/3 / 1/3

Sₙ = 6/3

Sₙ = 2