Q2 (10 points) Consider the function defined by 2x2 +a, if x 0 Which of the following lists only pairs a and b that make lim f(x) exist? x-+0 O b = 0 and a = 1, b = 0 and a = 0, b = 1 and a = 2, b = 2 and a = 3 O b = 0 and a = 0, b = 2 and a = 4, b = 3 and a = 6, b = 1 and a = 1 O b = e and a = 2e, b = 0 and a = 0, b = 2 and a = 4, b = 1 and a = 2 O b = ; and a = 1, b = -1 and a = -2, b = n and a = 2x, b = -2 and a = -3