Let f be the function defined by f(x)=ax2+bx+22x2−8, where a and b are constants. The graph of f has a horizontal asymptote at y=3, and f has a removable discontinuity at x=2. (a) Show that a=6 and b=−13. 2 (b) To make f continuous at x=2, f(2) should be defined as what value? Justify your answer.