In the version Mathemaica 10.4, I am very surprised that the core function
Coefficient has changed, e.g.,
Coefficient[3 x x + 8 y y - 24 x y, 2 x y]
In previous versions (e.g. v9.0.1, v10.1.0), the result was
-12. On the website wolframalpha, the result is still
-12. According to comments, it seems like the change has happened from v10.1.0 to v10.2.0.
Yes, this change is very small, but I feel it is very dangerous for my previous research code. How do I know about these kind of changes in new versions? Is there a list explaining such changes?