Use Exercise 33 to prove the hockeystick identity from
Chapter 9, Problem 37E(choose chapter or problem)
Use Exercise 33 to prove the hockeystick identity from Exercise 27. [Hint: First, note that the number of path s from (0, 0) to (n + 1 , r) equals Second, count the number of paths by summing the number of these paths that start by going k units upward for k = 0,1, 2,…, r .]
Unfortunately, we don't have that question answered yet. But you can get it answered in just 5 hours by Logging in or Becoming a subscriber.
Becoming a subscriber
Or look for another answer