Obtain inequality (5), Sec. 117.
Suggestion: Let R be larger than the numbers |xj|(j = 1,2,..., n−1). Note that if R is sufficiently large, the inequalities |z|/2<|z – xj|<2|z| hold for each xj when |z| > R. Then use expression (1), Sec. 117. along with conditions (5), Sec. 116.