**For the geometric sequence whose second term is 64 and whose fifth term is -8, find the value of the 9th term.**

**Answer:**

A2 = a*r = 64
A5 = a*r^4 = -8

Where a is the first term and r is the coming reason of the geometric series

Now A4/A2 = a

*r^4/a*r

=> r^3 = -8/64

=> r^3 = -1/8

=> r = -1/2

Now, a*r = 64

=> a = 64/r

=> a = -128

A9 = a*r^8 = -128/256 = -1/2