Define the function f by
f(x)=⎩⎨⎧x−2x2−4,∣x−2∣+a,ln(x−4),x<2,2≤x<5,x≥5,
where a is a real constant.
(a) Evaluate x→2−limf(x).
(b) Evaluate x→2+limf(x) in terms of a.
(c) Find the value of a that guarantees f is continuous at x=2 and justify your result.
(d) Using your value of a, state all intervals on which f is continuous and explain how you arrived at each interval.