Consider the function
f(x)=⎩⎨⎧mx2+3,7,x+5,x<2,x=2,x>2,
where m is a real constant.
a. Part 1: (a) Determine x→2−limf(x).
b. Part 2: (b) Determine x→2+limf(x).
c. Part 3: (c) Find the value of m (if any) that guarantees x→2limf(x) exists.
d. Part 4: (d) For the value of m found in part (c), decide whether f is continuous at x=2. Justify your conclusion by explicitly referencing the definition of continuity.