Question

Which is a recursive formula for the sequence 99.4, 0, –99.4, –198.8, where f(1) = 99.4?

Answer 1

Notice that in our sequence is

`0-99.4=-99.4`
`-99.4-99.4=0`
`-198.8-99.4=99.4`...

So we are dealing with an arithmetic sequence with difference -99.4.

Each term is build up "adding" `-99.4` to prior term.

So the recursive formula is

`f(n)=f(n-1)+(-99.4)`