write a function and formula or say if it doesn't exist

(a) f(x) is decreasing and concave down on (0, ), and limx f(x) = .

(b) f(x) is decreasing and concave up on (0, ), f(8) = 101, and limx f(x) = 3

(c) The graph of f has horizontal asymptotes y = 1 and y = 2, as well as a removable discontinuity at x = 3.

(d)f(x) is differentiable everywhere except at x = 3 and also satisfies lim x3 f'(x) = lim x3+ f'(x).