Wait, wah...? Partial Fractions and Derivative Proof, I think..?

Full proof:

Additional resource:



Basically just do the same thing you do for a normal partial fraction problem, just with 10x more symbols and a little bit of reasoning. There's a sketchy part in expressing the product from m=1 to j-1 when j can very well be 1. I can easily do a piece-wise solution (when j = 1, when j = n, and otherwise), but you get the idea of the proof anyway. And by "two of the three terms", I mean either the A1 term remains, or the An term remains, or Aj remains where 1 < j < n.


EDIT: Long time no see, guys.

0.o im in 10th grade and i think my brain just exploded. THIS IS MATH ISNT IT?? THIER ARE NO NUMBERS??