Let f x lim f x I 1 10 I 1 f 1 35 I 8 Compute the quantities below Write DNE if the limit does not exist or the value is undefined lim f x I 1 if a 1 if x 1 Since the above three quantities are not all defined discontinuous at x 1 we know that f is List ALL numbers at which f is discontinuous Be sure to check the functions defined to the left and right of 1 for discontinuities