On the previous note in this series we learnt / revised that
That's the formula when the difference () is so what would the formula be if
Let's denote the whole thing as
So let's say that , and what equation would we get from that.
We're going to have to use a different method to last time to solve this.
Since and we can put those in to get
That can be written as
This is basically a simplified version of the previous equation with a added in to account for the difference. This formula however is still flawed as it can only handle a constant variable for .