Afunction f ( x ) is said to have a removable discontinuity at x = a if: 1. f is either not defined or not continuous at x = a . 2. f ( a ) could either be defined or redefined so that the new function is continuous at x = a . let f ( x ) = 2 x 2 + 4 x − 48 x − 4 show that f ( x ) has a removable discontinuity at x = 4 and determine what value for f ( 4 ) would make f ( x ) continuous at x = 4 . must define f ( 4 ) = .