Question

quantos termos tem a pg (1/2 , 3/4 , ... ,81/32)

Answer 1

a1 = 1/2
a2 = a1q = 3/4
q = a2 / a1 = 3/4 : 1/2 = 3/4 * 2/1 = 6/4 = 3/2 ****
an = 81/32

81/32 = 1/2 *( 3/2 )^(n-1)
(3/2)^(n-1)  =  81/32 : 1/2 = 81/32 * 2/1 = 162/32 = 81/16 = 3^4 / 2^4  = (3/2)^4
( 3/2)^(n-1)  = ( 3/2)^4
n - 1 = 4
n = 4 + 1
n = 5 *****