Question

Find the 15th term of the geometric sequence 8,32,128

Answer 1

2147483648

Explanation:

Write the geometric sequence as an explicit formula

`8,\,32,\,128\rightarrow8(4)^0,8(4)^1,8(4)^2\rightarrow a_n=a_1r^(n-1)\rightarrow a_n=8(4)^(n-1)`

Find the n=15th term

`a_(15)=8(4)^(15-1)=8(4)^(14)=8(268435456)=2147483648`