5. Does the following equation specify a function with an independent variable x? If yes, find the domain of the function. If not, explain briefly. (a) y(x + y) = 4 (b) x(x + y) =4 (c) x3 - yz = 0 (d) x2 + y? = 16 (e) vx - y' = 0 6. Let f: R - R be a function defined by f(x) = 15 - 2x| - 12x - 231. (a) Write f (x) as a piecewise linear function. (b) Find the range of f. Show your steps. 7. Let f: R - R be defined by f(x) = 3 - x - |x - 1|. (a) Write f(x) as a piecewise linear function. (b) Evaluate f (3) and f(-1) respectively (c) Sketch the graph of y = f(x). (d) Let g: R - R be defined by g(x) = f(x - 1) + f(-x -1). (i) Prove that g is an even function, i.e., g(x) = g(-x) for every x e R. (ii) Hence, sketch the graph of y = g(x), then evaluate g (2022) and g(-1) respectively