Question 443251
Find all numbers for which the rational number is undefined. 
p^3-9p/p^2-16
.
It is only undefined if the denominator is zero so:
p^2 - 16 = 0
(p-4)(p+4) = 0
p = {4, -4}
.
So, the numbers that would make it undefined are:
-4 and 4