Decreasing function integral

Nov 2012
53
9
Mexico
Hi, everybody! I'm just taking my first integral calculus course, so I'm having a little trouble with some things. I hope you can guide me to prove this:

"If f is a decreasing function on [a, b], prove that f is integrable."

Thanks!
 

Plato

MHF Helper
Aug 2006
22,508
8,664
"If f is a decreasing function on [a, b], prove that f is integrable."
A decreasing function on \(\displaystyle [a,b]\) then the set of discontinuities is countable.
That means the function is Riemann integrable.
 
  • Like
Reactions: 2 people