****C++****

5.5 Consider these functions: double f(double x) { return g(x) + sqrt (h (x)); } double g (double x) { return 4 * h(x); } double h (double x) { return x * x + k (x) - 1; } double k (double x) { return 2 * (x + 1); } Without actually compiling and running a program, determine the results of the following function calls: a. double x1 = f(2); b. double x2 = g(h (2)); c. double x3 = k (g (2) + h (2)); d. double x4 = f(0) + f(1) + f (2); e. double x5 = f(-1) + g(-1) + h (-1) + k(-1)