Question

PROGRESSÃO GEOMÉTRICA (PG)

A) a1 = 520 e a2 = 520

B) a5 = 10000 e q = 10

C) a2 = -12 e q = 3

Answer 1

Explicação passo-a-passo:

a)

=> Razão

$\sf q=\dfrac{a_2}{a_1}$

$\sf q=\dfrac{520}{520}$

$\sf \red{q=1}$

$\sf \red{PG(520,520,520,520,520,\dots)}$

b)

=> Primeiro termo

$\sf a_n=a_1\cdot q^{n-1}$

$\sf a_5=a_1\cdot q^4$

$\sf 10000=a_1\cdot10^4$

$\sf 10000=a_1\cdot10000$

$\sf a_1=\dfrac{10000}{10000}$

$\sf \red{a_1=1}$

$\sf \red{PG(1,10,100,1000,10000,100000,\dots)}$

c)

=> Primeiro termo

$\sf a_2=a_1\cdot q$

$\sf -12=a_1\cdot3$

$\sf a_1=\dfrac{-12}{3}$

$\sf \red{a_1=-4}$

$\sf \red{PG(-4,-12,-36,-108,-324,\dots)}$