Ben Torah-
I can’t answer for “anon for this” since I know very little about her (although I think she’s an engineer).
What I could tell you is that when I took Differential Equations I used the outline for extra help with Laplace Transforms. Have I used it since then? Probably not.
What is the purpose of learning all these things?
There are a couple of answers:
1. It was part of a course that I was required to take to graduate, and there’s now way I could have gotten the job that I have without a college degree. The hiring manager who made me the offer said he wouldn’t consider a candidate without a college education since they can bluff their way through an interview but the only way to know for sure if they are capable of performing the tedious calculations is to see how they performed in these upper level math courses.
2. As was mentioned in a different thread last year- equations for a mathematician are like tools for a plumber. A plumber will buy some tools that he’ll never use just in case he ever needs it. There was a riddle that Squeak posted in “The Riddle Thread…” which I solved using a function that I only used in one other time.
3. Many courses are more for the discipline than for the material. These upper level math courses teach students more how to look at the equation and know how to tackle it than how to solve a specific problem.
So to answer your question- she probably doesn’t use Fourier Transforms but the learning it and understanding it is what actually helps her today.