Find the 6th term of a geometric sequence

Question

Find the sixth term of a geometric sequence if the first term is 2 and the common ratio is -2

Answer 1

This is very simple

 

All you need to do is apply your formula

 

a  is the first term of GS

 

r is the ratio

 

and n is the number of term you need

 

Formula to use is a*r^(n-1)

 

Assuming you are looking for the second term

 

n -1 will be come 2 -1 =1

 

r^(2-1) = r

 

Now we are looking for the 6th term

 

n-1 here is 6 -1 =5

 

r^(5)

 

We were given a = 2, and r = -2

 

a* r^(n-1)

 

2 *  (-2) ^ (6-1)

 

=2 * (-2)^(5)

 

Use your calculator to get this

 

Hope it helps