Question

Determine o 15° termo da PG (256,128,64,32...)

Answer 1

a15 = a1q^14 
a1 = 256 
q = a2/a1 = 128/256 = 1/2 
an = ? 
an = a1q^n-1 
an = 256(1/2)^n-1 
n = 15 
a15 = 256(1/2)^14 
a15 = 256(1/16384) 
a15 = 256/16384 
a15 = 1/64 ************** 

pg = 256, 128, 64, 32, 16, 8, 4, 2 , 1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64