1. Let a be a positive real number. In Part (1) of Theorem 3.25, we proved that for each real number x, jxj < a if and only if a < x < a. It is important to realize that the sentence a < x < a is actually the conjunction of two inequalities. That is, a < x < a means that a < x and x < a. ? (a) Complete the following statement: For each real number x, jxj a if and only if . . . . (b) Prove that for each real number x, jxj a if and only if a x a. (c) Complete the following statement: For each real number x, jxj > a if and only if .