Question

Use the initial term and the recursive formula to find an explicit formula for the sequence an. Write your answer in simplest form.

a1= 40

an= 5an–1

Answer 1

It's a geometric sequence where
`r=5`.

`a_n=ar^(n-1)`

Therefore

`a_n=40\cdot5^(n-1)=8\cdot5\cdot5^(n-1)=8\cdot5^n`