## 2.2 Analysis of Compound Interest

### Compound Interest with Regular Additions or Withdrawals

Note: if you cannot remember the basic recursive formula for a compound interest system, revise notes for 2.1 Simple and Compound Interest.

- A
**compound interest**system with regular additions or withdrawals has both a percentage increase/decrease and a fixed amount increase/decrease at each compounding period. - This type of system can be modelled using the following
**recursive formula**: