If R = [ p q q r ], write out R 2 and check that it is positive definite unless R is
Chapter 6, Problem 6.1.10(choose chapter or problem)
If R = [ p q q r ], write out R 2 and check that it is positive definite unless R is singular.
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