Is there any "good" definition for what constitutes "applied mathematics"?
Wikipedia lists stuff such as statistics, optimization. However, e.g these have certainly "pure mathematical" aspects to them. So what makes them "applied mathematics"?
Or what would make "pure mathematics" not "applied mathematics"? Is the distinction arbitrary (e.g. because even if something initially seems like it doesn't have applications, then it could be, that we just haven't seem them yet)?
Based on this I'd say the distinction is arbitrary. Rather, there's just mathematics and applications of mathematics.