u/IVIIVIXIVIIXIVII

In my time series course we’re taught how to show stationarity by hand through use of Expectations and differencing. However the homework is just look at scatter plots + ACF/PACF graphs and go from there. The professor swears that every tool you use, you should be able to derive. The majority of my classes just introduce concepts rather than diving in deep, since the goal of the program is exposure so I’m worried I’m doing the least.

I guess I’m just wondering if there’s any leeway to applying a tool if you don’t necessarily know it from the ground up?