Consider the function below. f(x, y) = In(x + y - 8) (a) Evaluate f(3, 6). (b) Evaluate f(e, 8). (c) Find the domain of f. Ox> 8 Oy> 8 Ox+y> 8 Ox+y-8>1 Ox> 8, y> 8 (d) Find the range of f. (Enter your answer using interval notation.) 4