Difference Equations



Difference equations are just discrete versions of differential equations. This seems to be a subject that isn't taught frequently. We can use them to explicitly solve for the terms in the Fibonacci sequence (like in the picture), and can also use them to sometimes solve for the terms in series solutions to differential equations (it always bothered me that we didn't). They also show up frequently in financial contexts, especially within Time Series in the context of Machine Learning. Moreover, they're just awesome.