In this problem we consider three functions f, and check that they satisfy the Direct Substitution Property at a = 0. The first two functions satisfy the condition with a two-sided limit; i.e., lim f(z) = f(0). 2-10 The third function is only defined for r 2 0, so we can only check the property for a one-sided limit: lim f(z) = f(0). In order to use the E/ 8 definition to prove the first of these statements, one must give a definition of o in terms of e such that 0 If(x) - f(0)|