1. Find the infimum and supremum of each of the following sets.

(a) E = {4,3,2,1,8, 7,6,5}.

(b) E = {x E R: x 2 - 3x - 5 = a}.

(c) E = [a, b), where a < b are real numbers.

(d) E = {plq E Q : p2 < 2q2 and p, q > a}.

(e) E = {x E R: x = 1 + (-l)n for n EN}.

(f) E = {x E R : x = lin - (_l)n for n EN}.

(g) E = {I + (-l)nln: n EN}.