What is the 11th term of the sequence: 2, 8, 32, 128....?

Question

31574 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-10-02T14:58:35

The 11th term is #2,095,152#

This is a geometric sequence, since each term after the first is obtained by multiplying a common ratio, #r#.

The common ratio is #4#. The first term, #a#, is #2#. The number of terms, #n# is #11#.

We use the formula #t_n = a xx r^(n- 1)# to determine the nth term in a geometric sequence.

#t_11 = 2 xx 4^(11 - 1)#

#t_11 = 2,095,152#

Hopefully this helps!

Answer 2 · 2016-10-02T15:05:24

#a_11=2097152#

Find the 11th term of the sequence 2,8,32, 128...

This is a geometric sequence because to find the next term, the previous term is multiplied by 4.

This number is referred to as the common ratio, or #r#.

A geometric sequence follows the rule

#a_n=a_1r^(n-1)# where

#a_n=# the #nth# term of the sequence
#a_1=#the first term in the sequence
#r=# the common ratio

In this example, #n=11#, #a_1=2# and #r=4#

#a_11=2*4^(11-1)=2*4^10=2*1048576=2097152#