Question

Given the first term and the common ratio of a geometric

sequence find the first five terms and the explicit formula.
a1 = - 4, r = 6

Answer 1

331776

Explanation:

The formula for geometric

sequence is given below

ar^n-1

Where a= first term, r= common ratio

From the question, a1 = - 4, r = 6 , n= 5

Then if we substitute, we have

ar^n-1

5th term= ar^n-1

= (-4×6)^(5-1)

=-24 ^ 4

=331776

Hence, the first five terms is =331776

The formula is 5th term= ar^(5-1)