The first two terms of a geometric sequence are a1 = 1⁄3 and a2 = 1⁄6. What is a8, the eighth term?

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Answer 1 · 2016-08-12T15:04:32

Use the formula #t_n = a xx r^(n - 1)#

Let's first find the value of #r#, the common ratio.

#r = t_2/t_1#

#r = (1/6)/(1/3)#

#r = 1/6 xx 3#

#r = 1/2#

Now we can us the formula.

#t_n = a xx r^(n - 1)#

#t_8 = 1/3 xx (1/2)^(8 - 1)#

#t_8 = 1/8 xx 1/128#

#t_8 = 1/1024#

Hopefully this helps!