This exercise is based on the following functions. f(x) = x2 + 2 with domain (-co, +0o) g(x) = x - 2 with domain (-co, +0o) h(x) = x + 6 with domain [27, +co) u(x) = Vx + 27 with domain [-27, 0) v(x) = V 27 - x with domain [0, 27] (a) Write a formula for the indicated function. d = g -f d( x ) = (b) Give the domain. (Enter your answer using interval notation.) (c) Specify the function's value at the given point a = -1, if defined. (If an answer is undefined, enter UNDEFINED.) d(-1) =