Question

A geometric sequence is defined by the explicit formula `a_n = 3(-5)^(n-1)`, what is the recursive formula for the nth term of this sequence?

Answer 1

`a_1=3; a_(n+1)=a_n(-5)`

Explanation:

The first term (`a_1`) is 3.

The second one (`a_2`) is obtained by multiplyng `3*(-5)`

The third one (`a_3`) by multiplying `3*(-5)(-5)=a_2*(-5)`

and so on.

Then

`a_1=3; a_(n+1)=a_n(-5)`