Question

Find an explicit formula for the geometric sequence -1,-7,-49,-343,.... Note : the first term should be d(1) . d(n) =

Answer 1

Answer:

dn = -7^n-1

Step-by-step explanation:

Given the sequence -1,-7,-49,-343,....

We are to find the nth term of the sequence

dn = ar^n-1

a is the first term = -1

r is the common ration = -7/-1 = -49/-7 = 7

n is the number of terms

Substitute

dn = -1(7)^n-1

dn = -7^n-1

hence the nth term of the sequence is dn = -7^n-1