# What is the tenth term of the geometric sequence with a4 = 16 and r = 2?

##### 1 Answer

Feb 23, 2016

1024

#### Explanation:

for the standard 'Geometric sequence' , the terms are

a , ar ,

#ar^2 , ar^3 , ar^4 ,....................,ar^(n-1)# where a , is the 1st term , r is the common ratio and the

nth term =#ar^(n-1)#

To find any term in the sequence , the nth term is used. To use it , requires knowing a and r .To find a.

use

# a_4 = ar^3 = 16 rArr a = 16/r^3 = 16/2^3 = 16/8 = 2 # now

# a_10 = ar^9 = 2(2)^9 = 1024#