Find a2 of the geometric sequence if a5 is 12 and a8 is 3/2

asked Oct 17, 2023 105k views

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3 votes

And

$a_5=a_1\cdot r^(5-1)=a_1\cdot r^4$
$a_8=a_1\cdot r^7$
$a_5\cdot r^3=a_8$
$12\cdot r^3=(3)/(2)$
r^3=(3)/(24)

$r=\sqrt[3]{(3)/(24)}$

So,

$a_2=(a_5)/(r^3)_{}$
a_2=(12)/((3)/(24))

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