1.4 Functions, Countability, and the Algebra of Sets 1.

(a) f-l(X) = (x + 7)/3.

(b) f-l(x) = l/logx.

(c) f-l(X) = arctanx. (d)

f-l(X) = (-3 + )33 + 4x)/2.

(e) f-l(X) = (x - 2)/3 when x ~ 2, f-l(x) =

X - 2 when 2 < x ~ 4, and f-l(X) = (x + 2)/3 when x > 4.

(f) f-l(x) =

(1 - )1- 4x2 )/2x when x =1= 0, and

f- 1 (0) = o.