I have wandered into the realm of signal processing and am currently focusing on learning more about filtering signals. I am currently trying to understand how to think about and solve a practice problem from my theory book. Given the signal
which one of the following signals corresponds to the high-pass version of the above signal?
I am not sure at all how to reason about this. If the signals were plotted in the frequency domain, the high-pass version of the signal would be obvious to identify by looking at it's spectra. We would see heavily attenuated lower frequencies while the higher ones remain as before. In this case the signals are plotted against the sample index which I am not used to looking at and as such I don't know how to go about this problem. How can I build intuition for this?